WEBVTT 1 00:00:11.559 --> 00:00:15.080 Okay so, good morning everyone, thank 2 00:00:13.519 --> 00:00:17.640 you so much for being here and for this 3 00:00:15.080 --> 00:00:19.359 opportunity, my name is Lluis Casabona and 4 00:00:17.640 --> 00:00:21.279 today I will talk about organic Field 5 00:00:19.359 --> 00:00:24.359 Effect transistors for near infrared 6 00:00:21.279 --> 00:00:26.359 light detection so first of all what is 7 00:00:24.359 --> 00:00:30.000 Neo infrared like and why is it 8 00:00:26.359 --> 00:00:31.880 important Neo infrared or n light is a 9 00:00:30.000 --> 00:00:34.200 type of radiation that we can find next 10 00:00:31.880 --> 00:00:36.239 to the visible spectrum devices made 11 00:00:34.200 --> 00:00:37.480 with these materials usually exhibit 12 00:00:36.239 --> 00:00:40.039 excellent 13 00:00:37.480 --> 00:00:42.079 performances however for some specific 14 00:00:40.039 --> 00:00:43.719 applications they might present some 15 00:00:42.079 --> 00:00:47.239 limitations for instance in flexible 16 00:00:43.719 --> 00:00:49.719 applications and for spectral selective 17 00:00:47.239 --> 00:00:52.199 detection um to address these issues uh 18 00:00:49.719 --> 00:00:54.719 we can build organic photo detectors 19 00:00:52.199 --> 00:00:56.399 these devices are made with Organic 20 00:00:54.719 --> 00:00:59.039 semiconductors which are highly 21 00:00:56.399 --> 00:01:00.960 conjugated organic molecules or polymers 22 00:00:59.039 --> 00:01:03.960 based on carbon and 23 00:01:00.960 --> 00:01:05.720 hydrogen these materials offer some uh 24 00:01:03.960 --> 00:01:08.720 advantages for instance they are 25 00:01:05.720 --> 00:01:12.520 compatible with flexible substrates and 26 00:01:08.720 --> 00:01:12.520 um of with large area 27 00:01:13.200 --> 00:01:17.920 fabrication uh we can um we have 28 00:01:15.960 --> 00:01:19.640 different types of photo detectors photo 29 00:01:17.920 --> 00:01:21.840 conductors photo diodes and 30 00:01:19.640 --> 00:01:24.640 phototransistors one type of electronic 31 00:01:21.840 --> 00:01:26.799 device that we can use to build organic 32 00:01:24.640 --> 00:01:30.680 phototransistors are the so-called 33 00:01:26.799 --> 00:01:33.439 organic Field Effect transistors or oets 34 00:01:30.680 --> 00:01:35.280 ofets are three terminal devices where 35 00:01:33.439 --> 00:01:37.680 the current flow from two electrodes 36 00:01:35.280 --> 00:01:40.200 that we call source and the drain s and 37 00:01:37.680 --> 00:01:42.520 D can be modulated by the application of 38 00:01:40.200 --> 00:01:45.360 a voltage in the third electrode called 39 00:01:42.520 --> 00:01:47.479 the gate these devices can be easily 40 00:01:45.360 --> 00:01:49.719 integrated in electronic circuits and 41 00:01:47.479 --> 00:01:52.880 are relatively easy to 42 00:01:49.719 --> 00:01:56.039 fabricate one of the main challenges of 43 00:01:52.880 --> 00:01:58.240 n organic photod detectors is to find 44 00:01:56.039 --> 00:02:01.000 photoactive materials that are able to 45 00:01:58.240 --> 00:02:03.640 absorb near infrared photon 46 00:02:01.000 --> 00:02:05.560 in this work we focused our efforts in 47 00:02:03.640 --> 00:02:08.640 this molecule here that you can see here 48 00:02:05.560 --> 00:02:11.239 which is Y6 Y6 is an end type 49 00:02:08.640 --> 00:02:13.520 semiconductor that presents an absortion 50 00:02:11.239 --> 00:02:16.760 spectr like this one with a peak in the 51 00:02:13.520 --> 00:02:19.519 near infrared at 841 nanometers and 52 00:02:16.760 --> 00:02:22.440 therefore shows potential as a possible 53 00:02:19.519 --> 00:02:24.599 candidate for n photo detectors and this 54 00:02:22.440 --> 00:02:28.040 leads us to the main objective of this 55 00:02:24.599 --> 00:02:31.599 work we just to study the potential of 56 00:02:28.040 --> 00:02:33.720 oets made with this material Y6 as 57 00:02:31.599 --> 00:02:36.080 prospective candidates for organic 58 00:02:33.720 --> 00:02:38.000 photod detectors and to optimize the 59 00:02:36.080 --> 00:02:40.560 fabrication conditions of these 60 00:02:38.000 --> 00:02:43.159 devices so the methodology that we 61 00:02:40.560 --> 00:02:45.879 followed in this work is as follows 62 00:02:43.159 --> 00:02:48.879 first we fabricated our 63 00:02:45.879 --> 00:02:52.519 devices then we characterized the 64 00:02:48.879 --> 00:02:54.080 organic uh semiconductor thin layer by 65 00:02:52.519 --> 00:02:58.360 different techniques in particular we 66 00:02:54.080 --> 00:02:58.360 focused on the crystallinity of this 67 00:02:58.760 --> 00:03:04.519 layer 68 00:03:01.280 --> 00:03:07.360 uh next we electrically characterized 69 00:03:04.519 --> 00:03:09.480 this electrical devices the O fets by 70 00:03:07.360 --> 00:03:12.360 different electrical measurements and 71 00:03:09.480 --> 00:03:15.280 finally the best of fets were studied as 72 00:03:12.360 --> 00:03:17.680 organic phototransistors under n 73 00:03:15.280 --> 00:03:20.440 Illumination in the following slides we 74 00:03:17.680 --> 00:03:23.319 will see each one of these steps in more 75 00:03:20.440 --> 00:03:25.879 detail so how we fabricated our 76 00:03:23.319 --> 00:03:28.480 devices first we started with a silicon 77 00:03:25.879 --> 00:03:31.120 wafer as our starting substrate where 78 00:03:28.480 --> 00:03:33.799 highly doed silicon acted both as the 79 00:03:31.120 --> 00:03:35.640 gate electrode and the substrate and a 80 00:03:33.799 --> 00:03:37.080 thin silicon dioxide layer as the 81 00:03:35.640 --> 00:03:40.239 dialectric 82 00:03:37.080 --> 00:03:42.959 material then we evaporated the source 83 00:03:40.239 --> 00:03:46.599 and drain electrodes by means of 84 00:03:42.959 --> 00:03:48.959 photolithography uh here you can see the 85 00:03:46.599 --> 00:03:51.239 the shape of the electrodes that we used 86 00:03:48.959 --> 00:03:54.840 which are inter digitated 87 00:03:51.239 --> 00:03:56.680 electrodes after that we coated um the 88 00:03:54.840 --> 00:03:59.040 organic semiconductor layer with a 89 00:03:56.680 --> 00:04:00.879 technique that is called blade coating 90 00:03:59.040 --> 00:04:03.239 for this we previously prepared a 91 00:04:00.879 --> 00:04:06.480 solution of our Semiconductor in 92 00:04:03.239 --> 00:04:08.400 chloroform and then uh we applied this 93 00:04:06.480 --> 00:04:11.040 blade coating technique which consists 94 00:04:08.400 --> 00:04:13.760 on preparing a meniscus in the gap 95 00:04:11.040 --> 00:04:16.519 between a blade and the substrate and 96 00:04:13.760 --> 00:04:18.160 moving the blade forward th creating 97 00:04:16.519 --> 00:04:20.799 this homogeneous thin 98 00:04:18.160 --> 00:04:22.960 film this technique is compatible with 99 00:04:20.799 --> 00:04:25.759 roll to roll and large area 100 00:04:22.960 --> 00:04:27.639 fabrication and finally um we did a 101 00:04:25.759 --> 00:04:29.680 thermal analing of our devices which 102 00:04:27.639 --> 00:04:33.160 consists on heating them at different 103 00:04:29.680 --> 00:04:34.039 temperatures in our case between 110° 104 00:04:33.160 --> 00:04:37.160 and 105 00:04:34.039 --> 00:04:40.160 250° this step is extremely important as 106 00:04:37.160 --> 00:04:42.759 it allows us to obtain crystallinity of 107 00:04:40.160 --> 00:04:45.160 this particular organic semiconductor 108 00:04:42.759 --> 00:04:49.120 which enhances or typically enhances the 109 00:04:45.160 --> 00:04:51.120 performance device the device 110 00:04:49.120 --> 00:04:53.080 performances all of these steps took 111 00:04:51.120 --> 00:04:55.919 place inside of a glow box to avoid the 112 00:04:53.080 --> 00:04:55.919 gradation of our 113 00:04:55.960 --> 00:05:00.520 semiconductor here are the results of 114 00:04:58.000 --> 00:05:03.120 the thin film characterization 115 00:05:00.520 --> 00:05:05.720 um with the polarized Optical microscopy 116 00:05:03.120 --> 00:05:09.600 images we could see that samples are 117 00:05:05.720 --> 00:05:12.880 kned between 170 degrees and and 118 00:05:09.600 --> 00:05:15.680 230° uh showed crystalline domains this 119 00:05:12.880 --> 00:05:18.440 could also be observed um with the X-ray 120 00:05:15.680 --> 00:05:20.560 defraction uh measurements as we observe 121 00:05:18.440 --> 00:05:23.400 some Peaks for these temperatures 122 00:05:20.560 --> 00:05:26.199 however for the highest temperatures we 123 00:05:23.400 --> 00:05:29.560 also observed some partial de wetting uh 124 00:05:26.199 --> 00:05:30.319 which is undesirable and therefore 170 125 00:05:29.560 --> 00:05:33.280 and 126 00:05:30.319 --> 00:05:36.560 190° were considered the optimal ones to 127 00:05:33.280 --> 00:05:40.199 achieve crystallinity of our 128 00:05:36.560 --> 00:05:41.759 semiconductor with these um devices and 129 00:05:40.199 --> 00:05:45.039 also the ones at 130 00:05:41.759 --> 00:05:47.720 150 we perform some electrical 131 00:05:45.039 --> 00:05:51.000 measurements in particular the transfer 132 00:05:47.720 --> 00:05:54.400 measurement which consists on measuring 133 00:05:51.000 --> 00:05:57.600 the source and drain current as we sweep 134 00:05:54.400 --> 00:06:00.160 the source gate potential and by fitting 135 00:05:57.600 --> 00:06:02.479 this experimental data to 136 00:06:00.160 --> 00:06:04.880 this uh theoretical equation here we can 137 00:06:02.479 --> 00:06:07.039 extract the two figures of Merit of of 138 00:06:04.880 --> 00:06:09.319 fets which are the Field Effect Mobility 139 00:06:07.039 --> 00:06:10.960 which quantizes the ease with which 140 00:06:09.319 --> 00:06:13.680 charge carriers move along a 141 00:06:10.960 --> 00:06:15.680 semiconductor and the thresold voltage 142 00:06:13.680 --> 00:06:17.759 which is the minimum voltage that we 143 00:06:15.680 --> 00:06:20.520 need to apply to induce a pressable 144 00:06:17.759 --> 00:06:23.639 current in our 145 00:06:20.520 --> 00:06:27.000 device our results show that for 146 00:06:23.639 --> 00:06:30.240 crystalline samples the ones at 170 and 147 00:06:27.000 --> 00:06:32.080 190 the mobility values and therefore 148 00:06:30.240 --> 00:06:34.240 the performance of our device were 149 00:06:32.080 --> 00:06:36.120 significantly higher than for the amoros 150 00:06:34.240 --> 00:06:39.039 sample which is what we 151 00:06:36.120 --> 00:06:41.560 expected uh moreover in particular the 152 00:06:39.039 --> 00:06:44.120 the highest value was around 0.1 for the 153 00:06:41.560 --> 00:06:44.120 samples at 154 00:06:44.880 --> 00:06:50.360 170 uh regarding the thresold voltage we 155 00:06:47.560 --> 00:06:51.759 could see that uh we achieved values 156 00:06:50.360 --> 00:06:53.759 positive values for the crystalline 157 00:06:51.759 --> 00:06:56.520 samples which is what we expect for an 158 00:06:53.759 --> 00:06:56.520 end type organic 159 00:06:57.840 --> 00:07:03.319 semiconductor the best device es an at 160 00:07:00.479 --> 00:07:06.680 170 were later characterized under 161 00:07:03.319 --> 00:07:09.000 illumination as organic 162 00:07:06.680 --> 00:07:11.639 phototransistors uh to do so we send 163 00:07:09.000 --> 00:07:13.800 some light pulses to these devices and 164 00:07:11.639 --> 00:07:16.560 here you can see an example of a dynamic 165 00:07:13.800 --> 00:07:18.680 measurement where you can clearly see 166 00:07:16.560 --> 00:07:20.599 how the current increases significantly 167 00:07:18.680 --> 00:07:24.360 when there is light insiding on the 168 00:07:20.599 --> 00:07:26.800 device um yeah El light from the 169 00:07:24.360 --> 00:07:29.919 amplitude of these steps we can extract 170 00:07:26.800 --> 00:07:33.520 the photor responsi photoresponsivity 171 00:07:29.919 --> 00:07:36.560 which is a key parameter to quantify the 172 00:07:33.520 --> 00:07:36.560 performance of a photo 173 00:07:36.680 --> 00:07:41.840 transistor um by performing several 174 00:07:39.639 --> 00:07:43.319 measurements like this one under SE 175 00:07:41.840 --> 00:07:46.039 under different 176 00:07:43.319 --> 00:07:47.400 conditions we could obtain these results 177 00:07:46.039 --> 00:07:50.319 which show that for different 178 00:07:47.400 --> 00:07:53.520 polarizations of our transistors the 179 00:07:50.319 --> 00:07:56.280 same tendency between responsivity of 180 00:07:53.520 --> 00:07:59.720 the device and incident Optical power or 181 00:07:56.280 --> 00:08:01.840 intensity of the incident light uh is as 182 00:07:59.720 --> 00:08:03.639 follows uh which follows this equation 183 00:08:01.840 --> 00:08:06.240 that you can see on top of the 184 00:08:03.639 --> 00:08:09.960 slide where this relationship is not 185 00:08:06.240 --> 00:08:13.599 lineal but um uh we have this relation 186 00:08:09.960 --> 00:08:16.120 where beta is always lower than one this 187 00:08:13.599 --> 00:08:18.560 shows that at lower incident Optical 188 00:08:16.120 --> 00:08:20.680 Powers we get higher response of our 189 00:08:18.560 --> 00:08:23.120 device and this leads us to the main 190 00:08:20.680 --> 00:08:27.479 conclusions of our work which is that we 191 00:08:23.120 --> 00:08:31.680 could successfully fabricate y60 feds um 192 00:08:27.479 --> 00:08:36.120 we also saw that uh a polymorph Y6 can 193 00:08:31.680 --> 00:08:38.719 be achieved aning at 170 and 190 degrees 194 00:08:36.120 --> 00:08:40.440 and that this Crystal in structures also 195 00:08:38.719 --> 00:08:43.640 provided the best performance of our 196 00:08:40.440 --> 00:08:45.120 device and finally we saw that um at 197 00:08:43.640 --> 00:08:48.399 lower incident Optical Powers we 198 00:08:45.120 --> 00:08:50.440 achieved higher response which uh aligns 199 00:08:48.399 --> 00:08:54.240 with the objective to be able to detect 200 00:08:50.440 --> 00:08:57.880 lower low quantities of incident 201 00:08:54.240 --> 00:09:01.000 light all in all Y6 is a potential 202 00:08:57.880 --> 00:09:03.600 candidate for our Ric photo transistors 203 00:09:01.000 --> 00:09:05.360 and uh further optimizations both in 204 00:09:03.600 --> 00:09:07.839 Silicon and in flexible substrates 205 00:09:05.360 --> 00:09:10.200 should be carried out and in the future 206 00:09:07.839 --> 00:09:12.279 hopefully apply these devices in real 207 00:09:10.200 --> 00:09:15.560 applications such as poo 208 00:09:12.279 --> 00:09:18.160 Symmetry and well thank you I would like 209 00:09:15.560 --> 00:09:20.519 to thank simat for this opportunity and 210 00:09:18.160 --> 00:09:23.320 to all my mmap fellows with whom I 211 00:09:20.519 --> 00:09:24.440 enjoyed a lot carrying out this project 212 00:09:23.320 --> 00:09:25.720 and that's all thank you so much for 213 00:09:24.440 --> 00:09:26.839 your attention if you have any questions 214 00:09:25.720 --> 00:09:31.120 please feel free to ask I will be 215 00:09:26.839 --> 00:09:31.120 delighted to try to answer them 216 00:09:34.839 --> 00:09:41.360 I have question to the first to the 217 00:09:38.120 --> 00:09:41.360 slide six 218 00:09:49.480 --> 00:09:52.480 yes 219 00:09:52.680 --> 00:09:58.120 okay it seems that the better 220 00:09:55.519 --> 00:10:01.120 personality is obtain 221 00:09:58.120 --> 00:10:01.120 for7 222 00:10:06.880 --> 00:10:15.000 um yeah for the it is true that for the 223 00:10:11.399 --> 00:10:17.440 170° um only one Peak is observed and 224 00:10:15.000 --> 00:10:21.040 with very low intensity the pigs could 225 00:10:17.440 --> 00:10:24.560 be observed um but the scale was uh very 226 00:10:21.040 --> 00:10:26.640 yeah the pigs were not as as significant 227 00:10:24.560 --> 00:10:31.480 as the ones at 228 00:10:26.640 --> 00:10:33.320 190 because it's almost yeah um actually 229 00:10:31.480 --> 00:10:34.680 here maybe the image is not super clear 230 00:10:33.320 --> 00:10:36.920 and compared with the 231 00:10:34.680 --> 00:10:38.959 190 um it is true that here you can 232 00:10:36.920 --> 00:10:42.399 clearly see the crystalling domains and 233 00:10:38.959 --> 00:10:44.480 here it's almost in the middle between a 234 00:10:42.399 --> 00:10:47.440 morphos and 235 00:10:44.480 --> 00:10:50.920 crystalline actually 236 00:10:47.440 --> 00:10:53.240 um so you could observe some crystalling 237 00:10:50.920 --> 00:10:54.800 domains when we when we did the 238 00:10:53.240 --> 00:10:57.880 electrical characterization of our 239 00:10:54.800 --> 00:10:59.279 samples we expected the 190° samples to 240 00:10:57.880 --> 00:11:01.639 perform to have a better better 241 00:10:59.279 --> 00:11:05.519 performance than the on at 242 00:11:01.639 --> 00:11:06.360 170 and what we think it happens is that 243 00:11:05.519 --> 00:11:09.040 at 244 00:11:06.360 --> 00:11:12.320 190 there might be some micr structural 245 00:11:09.040 --> 00:11:14.079 defects that we cannot observe uh with 246 00:11:12.320 --> 00:11:17.800 polarized microscopy 247 00:11:14.079 --> 00:11:21.440 images and this 248 00:11:17.800 --> 00:11:23.920 um decreases the performance of our 249 00:11:21.440 --> 00:11:25.920 device and maybe we should use other 250 00:11:23.920 --> 00:11:29.839 characterization techniques to further 251 00:11:25.920 --> 00:11:32.040 uh Analyze This okay thanks you welcome 252 00:11:29.839 --> 00:11:32.040 thank you 253 00:11:57.959 --> 00:12:00.959 254 00:12:27.880 --> 00:12:30.880 thank you 255 00:12:33.000 --> 00:12:39.120 for see okay uh maybe English so uh thank 256 00:12:36.639 --> 00:12:43.440 you for presentation very interesting so 257 00:12:39.120 --> 00:12:45.880 I think the final um object is just 258 00:12:43.440 --> 00:12:49.160 human sensor no so this is a polymeric 259 00:12:45.880 --> 00:12:51.440 device and how it's have you consider 260 00:12:49.160 --> 00:12:53.040 studing how it affect by humidity or it 261 00:12:51.440 --> 00:12:56.040 is affected or something like that like 262 00:12:53.040 --> 00:12:58.399 the performance or yes um I don't know 263 00:12:56.040 --> 00:13:01.440 if it will show here um because I have I 264 00:12:58.399 --> 00:13:04.839 have extra light but they are 265 00:13:01.440 --> 00:13:08.519 hidden yeah um maybe I 266 00:13:04.839 --> 00:13:08.519 can I can look it 267 00:13:09.680 --> 00:13:15.480 up yeah so we did uh different stability 268 00:13:13.079 --> 00:13:17.279 tests of our devices because the organic 269 00:13:15.480 --> 00:13:19.560 semiconductors that we're using are 270 00:13:17.279 --> 00:13:22.800 known for not being the most St stable 271 00:13:19.560 --> 00:13:24.560 materials in air um the first stability 272 00:13:22.800 --> 00:13:27.320 test that we did was a bias stress where 273 00:13:24.560 --> 00:13:28.920 we measured um several times the 274 00:13:27.320 --> 00:13:31.760 transfer measurements the that 275 00:13:28.920 --> 00:13:34.519 measurements that I showed uh before and 276 00:13:31.760 --> 00:13:38.600 this was done 20 times and we can see a 277 00:13:34.519 --> 00:13:40.839 small shift here in the threshold 278 00:13:38.600 --> 00:13:44.440 voltage which is the minimum potential 279 00:13:40.839 --> 00:13:48.560 needed to switch on the 280 00:13:44.440 --> 00:13:50.800 device um and this these results were 281 00:13:48.560 --> 00:13:53.079 taken into account when when later doing 282 00:13:50.800 --> 00:13:56.560 the measurements under 283 00:13:53.079 --> 00:13:58.959 illumination and then I tried to test my 284 00:13:56.560 --> 00:14:01.759 devices in air because everything that I 285 00:13:58.959 --> 00:14:03.440 I did in this work was in a glow so in 286 00:14:01.759 --> 00:14:05.920 in and 287 00:14:03.440 --> 00:14:08.160 conditions so what I did was to take one 288 00:14:05.920 --> 00:14:11.079 of my devices 5 minutes out of the 289 00:14:08.160 --> 00:14:13.160 glowbox and then me um measure it again 290 00:14:11.079 --> 00:14:16.000 in the same uh 291 00:14:13.160 --> 00:14:18.360 equipment and you can see that the 292 00:14:16.000 --> 00:14:22.560 performance clearly uh 293 00:14:18.360 --> 00:14:25.160 diminishes so I yeah um in order to work 294 00:14:22.560 --> 00:14:27.000 with these devices in open air we should 295 00:14:25.160 --> 00:14:31.160 first 296 00:14:27.000 --> 00:14:32.759 um um code um yeah code them with other 297 00:14:31.160 --> 00:14:36.279 materials that are transparent in the 298 00:14:32.759 --> 00:14:38.800 near infrared um for them to work yeah 299 00:14:36.279 --> 00:14:38.800 thank you for the question 300 00:14:47.600 --> 00:14:52.519 good morning to everyone 301 00:14:50,440 --> 00:14:55,360 I'm going to start the presentation of my 302 00:14:52.519 --> 00:14:57.920 master thesis called processing of M 303 00:14:55.360 --> 00:15:00.120 tractus stainless Steels using fuse 304 00:14:57.920 --> 00:15:02.360 filament fabrication 305 00:15:00.120 --> 00:15:04.079 Advanced processing Technologies such as 306 00:15:02.360 --> 00:15:06.279 P injection molding and additive 307 00:15:04.079 --> 00:15:09.519 manufacturing are revolutionizing the 308 00:15:06.279 --> 00:15:11.079 way we design and manufactur components 309 00:15:09.519 --> 00:15:13.920 they are allowing us to combine 310 00:15:11.079 --> 00:15:16.240 different materials into a single piece 311 00:15:13.920 --> 00:15:19.759 taking advantage of the individual 312 00:15:16.240 --> 00:15:22.560 characteristics to obtain uh improved 313 00:15:19.759 --> 00:15:24.800 functionalities this opens up possib uh 314 00:15:22.560 --> 00:15:26.880 possibilities for a precise distribution 315 00:15:24.800 --> 00:15:29.040 of mechanical thermal electrical or 316 00:15:26.880 --> 00:15:30.720 chemical properties that with lead to 317 00:15:29.040 --> 00:15:33.240 the design of new 318 00:15:30.720 --> 00:15:35.120 applications achieving a high mechanical 319 00:15:33.240 --> 00:15:36.399 strength and tactility in the Steels is 320 00:15:35.120 --> 00:15:40.519 a longstanding 321 00:15:36.399 --> 00:15:42.360 challenge uh to get a a good balance 322 00:15:40.519 --> 00:15:44.759 between these two properties the current 323 00:15:42.360 --> 00:15:47.800 trend is to to apply thermomechanical 324 00:15:44.759 --> 00:15:50.120 treatments to the Steels to in order to 325 00:15:47.800 --> 00:15:51.959 get a uniform distribution of multiple 326 00:15:50.120 --> 00:15:54.680 phes in the micr 327 00:15:51.959 --> 00:15:58.880 structure uh however these multiac 328 00:15:54.680 --> 00:16:01.880 Steels as you can see uh have a limit a 329 00:15:58.880 --> 00:16:05.560 in the properties they can achieve so 330 00:16:01.880 --> 00:16:08.519 then several studies are showing that by 331 00:16:05.560 --> 00:16:11.079 alternating hard faces with soft faces 332 00:16:08.519 --> 00:16:12.839 in a mesoscopic scaling patterns is 333 00:16:11.079 --> 00:16:14.759 possible to achieve an exceptional 334 00:16:12.839 --> 00:16:17.600 combination of properties that is not 335 00:16:14.759 --> 00:16:21.399 possible by any other STS family these 336 00:16:17.600 --> 00:16:24.319 are called the mesas Steels and examples 337 00:16:21.399 --> 00:16:27.959 are the old damasus and the more recent 338 00:16:24.319 --> 00:16:29.480 multier Stills unfortunately uh 339 00:16:27.959 --> 00:16:31.839 conventional methods for producing 340 00:16:29.480 --> 00:16:35.120 multier steel Composites such as R 341 00:16:31.839 --> 00:16:36.959 bonded and Forge welding have some 342 00:16:35.120 --> 00:16:40.600 difficulties in obtaining complex 343 00:16:36.959 --> 00:16:44.519 geometries from uh raw material seats 344 00:16:40.600 --> 00:16:46.959 and also it had been seen that uh severe 345 00:16:44.519 --> 00:16:50.040 deformation operations favor the 346 00:16:46.959 --> 00:16:52.680 appearance of voids in the 347 00:16:50.040 --> 00:16:55.240 interfaces then additive manufacturing 348 00:16:52.680 --> 00:16:57.440 using multiple materials is a known 349 00:16:55.240 --> 00:17:00.600 technique but applying the multilayer 350 00:16:57.440 --> 00:17:02.920 still comet uh to this process is a 351 00:17:00.600 --> 00:17:07.120 newer and a greater area of 352 00:17:02.920 --> 00:17:08.880 interest uh currently mes structures uh 353 00:17:07.120 --> 00:17:11.760 have already been achieved by 3D 354 00:17:08.880 --> 00:17:14.640 printing by the direct type Technologies 355 00:17:11.760 --> 00:17:17.199 these are based on melting and this 356 00:17:14.640 --> 00:17:19.199 makes difficult to have a good control 357 00:17:17.199 --> 00:17:21.919 over the micr structure also it's 358 00:17:19.199 --> 00:17:24.959 possible to lose some alloying elements 359 00:17:21.919 --> 00:17:27.799 because of sulation and moreover cracks 360 00:17:24.959 --> 00:17:29.280 can form due to residual stresses from 361 00:17:27.799 --> 00:17:32.120 solidification 362 00:17:29.280 --> 00:17:34.320 so in this study we propose an 363 00:17:32.120 --> 00:17:35.400 Innovative approach by using fuse 364 00:17:34.320 --> 00:17:39.039 filament 365 00:17:35.400 --> 00:17:41.880 fabrication uh that is an indirect uh 366 00:17:39.039 --> 00:17:43.320 technology the process begin with by 367 00:17:41.880 --> 00:17:46.520 blending the metallic pwder with a 368 00:17:43.320 --> 00:17:48.520 binder that is then pelletized anded 369 00:17:46.520 --> 00:17:50.960 into a filament for printing after 370 00:17:48.520 --> 00:17:53.160 printing the binder has to be removed 371 00:17:50.960 --> 00:17:55.960 and we do this by a first solvent based 372 00:17:53.160 --> 00:17:58.960 debinding process followed by a thermal 373 00:17:55.960 --> 00:18:03.520 debinding and a cing stage 374 00:17:58.960 --> 00:18:05.679 uh the this is an indirect uh technology 375 00:18:03.520 --> 00:18:08.520 and that means that once you get the 376 00:18:05.679 --> 00:18:11.000 geometry you have to perform and to 377 00:18:08.520 --> 00:18:12.520 optimize more steps until you you get 378 00:18:11.000 --> 00:18:15.559 the final 379 00:18:12.520 --> 00:18:17.840 component uh this technology offers 380 00:18:15.559 --> 00:18:20.840 several advantages such as the good 381 00:18:17.840 --> 00:18:23.440 material combination flexibility and the 382 00:18:20.840 --> 00:18:26.559 most important one a good micr structure 383 00:18:23.440 --> 00:18:29.039 control however there are some uh 384 00:18:26.559 --> 00:18:32.720 challenges to to 385 00:18:29.039 --> 00:18:35.440 overcome in my in my work during the the 386 00:18:32.720 --> 00:18:37.919 master tesis I have focused on three 387 00:18:35.440 --> 00:18:40.799 main challenges the first one is related 388 00:18:37.919 --> 00:18:43.520 to the design of the fix stocks and the 389 00:18:40.799 --> 00:18:45.679 solution processes in order to obtain a 390 00:18:43.520 --> 00:18:48.880 windable printable 391 00:18:45.679 --> 00:18:51.320 filaments uh that is a very crucial 392 00:18:48.880 --> 00:18:54.640 process because all the the rest of the 393 00:18:51.320 --> 00:18:57.840 faces depends on the filament quality 394 00:18:54.640 --> 00:19:01.960 the second one is uh is to overcome 395 00:18:57.840 --> 00:19:05.520 overcome all the challenges using uh a 396 00:19:01.960 --> 00:19:07.720 two extruder printing process uh which 397 00:19:05.520 --> 00:19:11.039 involves the control of many parameters 398 00:19:07.720 --> 00:19:13.480 and requires a vast experience finally 399 00:19:11.039 --> 00:19:17.039 the highest complexity rely on the cing 400 00:19:13.480 --> 00:19:19.960 process when a rink cage uh takes place 401 00:19:17.039 --> 00:19:23.240 and compositional gradients are 402 00:19:19.960 --> 00:19:25.880 formed uh first we in this in this 403 00:19:23.240 --> 00:19:28.440 presentation I I will discuss combining 404 00:19:25.880 --> 00:19:32.880 uh two different stainless Steels uh 405 00:19:28.440 --> 00:19:35.520 tintic 316 L and A martic 174 pH 406 00:19:32.880 --> 00:19:38.480 searching for Unique com for a unique 407 00:19:35.520 --> 00:19:40.880 combination of mechanical and corrosion 408 00:19:38.480 --> 00:19:43.360 properties the challenges begin with the 409 00:19:40.880 --> 00:19:45.200 selection of raw materials both both 410 00:19:43.360 --> 00:19:47.440 patters have to s a similar 411 00:19:45.200 --> 00:19:50.280 compatibility with the binder so in this 412 00:19:47.440 --> 00:19:52.799 case we have selected uh PS with similar 413 00:19:50.280 --> 00:19:55.200 particle size particle size distribution 414 00:19:52.799 --> 00:19:59.799 similar uh 415 00:19:55.200 --> 00:20:01.760 morphology then uh the The Binding 416 00:19:59.799 --> 00:20:04.120 temperatures uh have to be similar in 417 00:20:01.760 --> 00:20:07.400 both materials so we have decided to use 418 00:20:04.120 --> 00:20:10.720 the same binder systems and finally we 419 00:20:07.400 --> 00:20:14.679 have maximized the solid loading uh to a 420 00:20:10.720 --> 00:20:17.320 60% in both fix stocks in order to to 421 00:20:14.679 --> 00:20:19.919 reduce the contraction during cering and 422 00:20:17.320 --> 00:20:23.720 make the process more 423 00:20:19.919 --> 00:20:26.320 controllable uh about printing with two 424 00:20:23.720 --> 00:20:29.520 extruders many considerations have to be 425 00:20:26.320 --> 00:20:32.400 taken in in account the first is the 426 00:20:29.520 --> 00:20:35.720 filament retraction that is is necessary 427 00:20:32.400 --> 00:20:38.080 while printing to avoid ooing but can be 428 00:20:35.720 --> 00:20:40.760 problematic causing damages in the 429 00:20:38.080 --> 00:20:43.600 filaments we have solved it by reducing 430 00:20:40.760 --> 00:20:45.960 the filament retraction distance and by 431 00:20:43.600 --> 00:20:49.799 developing uh filaments with enough 432 00:20:45.960 --> 00:20:52.960 enough stiffness also a crucial factor 433 00:20:49.799 --> 00:20:54.760 is the axis nuel cero calibration and 434 00:20:52.960 --> 00:20:57.000 even a slight deviation can cause 435 00:20:54.760 --> 00:21:00.039 catastrophic results during centering 436 00:20:57.000 --> 00:21:02.799 finally uh printing is a process subject 437 00:21:00.039 --> 00:21:05.799 to variations and this can lead to 438 00:21:02.799 --> 00:21:08.919 microscopic defects as you can see we 439 00:21:05.799 --> 00:21:11.640 have partially solve it by implementing 440 00:21:08.919 --> 00:21:14.520 a printing parameter called overlap that 441 00:21:11.640 --> 00:21:16.440 consist in setting a percentage of 442 00:21:14.520 --> 00:21:19.520 overlap between 443 00:21:16.440 --> 00:21:24.240 materials about Shing we have performed 444 00:21:19.520 --> 00:21:26.520 a cing study between 3 1360 and 14400 445 00:21:24.240 --> 00:21:29.480 Dees looking for the most suitable 446 00:21:26.520 --> 00:21:32.520 temperatures in terms of those factors 447 00:21:29.480 --> 00:21:36.520 for for both materials finally uh 448 00:21:32.520 --> 00:21:40.559 temperatures between uh 1360 and sorry 449 00:21:36.520 --> 00:21:44.200 1380 and 1390 degrees uh were considered 450 00:21:40.559 --> 00:21:46.480 valid and as you can see we have uh 451 00:21:44.200 --> 00:21:49.000 notice the contraction differences 452 00:21:46.480 --> 00:21:51.679 between both materials while 453 00:21:49.000 --> 00:21:53.640 cering however this didn't suppose a 454 00:21:51.679 --> 00:21:56.400 problem while obtaining final measure 455 00:21:53.640 --> 00:21:58.720 structures like the one in the 456 00:21:56.400 --> 00:22:03.480 slide finally 457 00:21:58.720 --> 00:22:06.120 uh uh cine is a diffusive uh process and 458 00:22:03.480 --> 00:22:09.159 this results in compositional gradients 459 00:22:06.120 --> 00:22:11.480 so to control this effect that is very 460 00:22:09.159 --> 00:22:13.120 important to obtain tailor properties we 461 00:22:11.480 --> 00:22:16.200 have performed chemical composition 462 00:22:13.120 --> 00:22:20.120 analysis and micro harnesses profiles in 463 00:22:16.200 --> 00:22:23.600 this diagram we we can see how the 464 00:22:20.120 --> 00:22:26.039 interfaces and the martic bands increase 465 00:22:23.600 --> 00:22:29.600 uh with the growing cing temperature 466 00:22:26.039 --> 00:22:32.080 also it is remarkable the good uh 467 00:22:29.600 --> 00:22:36.880 bonding mat materials that have been 468 00:22:32.080 --> 00:22:41.039 achieved as conclusions uh uh the three 469 00:22:36.880 --> 00:22:46.200 main challenges have been uh overcome 470 00:22:41.039 --> 00:22:48.679 first we have uh a 316l and a 174 pH 471 00:22:46.200 --> 00:22:50.520 windable and printable filaments valid 472 00:22:48.679 --> 00:22:54.600 to material printing have been 473 00:22:50.520 --> 00:22:56.840 developed uh the the challenges of 474 00:22:54.600 --> 00:22:58.679 printing with chers have be overcome 475 00:22:56.840 --> 00:23:02.440 obtaining free defects 476 00:22:58.679 --> 00:23:05.279 uh geometries and finally 477 00:23:02.440 --> 00:23:07.320 um final M structures have been achieved 478 00:23:05.279 --> 00:23:10.760 with a a good bonding between materials 479 00:23:07.320 --> 00:23:12.480 and a good M structor control so we have 480 00:23:10.760 --> 00:23:14.000 demonstrated that the fabrication of M 481 00:23:12.480 --> 00:23:16.520 structors with the fuse filament 482 00:23:14.000 --> 00:23:19.840 fabrication technique is possible and 483 00:23:16.520 --> 00:23:22.159 promising finally uh we have also found 484 00:23:19.840 --> 00:23:24.000 some difficulties while obtaining other 485 00:23:22.159 --> 00:23:26.840 geometries because of the stresses 486 00:23:24.000 --> 00:23:30.840 during cering so we are uh planning to 487 00:23:26.840 --> 00:23:32.880 work on on performing the latry test and 488 00:23:30.840 --> 00:23:36.240 uh analyzing the most suitable 489 00:23:32.880 --> 00:23:40.960 topologies to to improve to solve 490 00:23:36.240 --> 00:23:43.080 these issues and to uh obtain the the 491 00:23:40.960 --> 00:23:47.200 best mechanical and corrosion properties. 492 00:23:43.080 --> 00:23:51.159 So this work has the ground SE 493 00:23:47.200 --> 00:23:54.120 the ground for obtaining future 494 00:23:51.159 --> 00:23:58.200 complex geometries with a 495 00:23:54.120 --> 00:24:00.480 combination of other materials, obtain 496 00:23:58.200 --> 00:24:03.360 unprecedented tailor properties on 497 00:24:00.480 --> 00:24:05.720 groundbreaking application. 498 00:24:03.360 --> 00:24:05.720 Thank you 403 00:24:10.000 --> 00:24:12.920 Bueno, Juan, muy bien, muchísimas gracias. 404 00:24:12.960 --> 00:24:15.360 Muy fenomenal la presentación que has hecho. 405 00:24:15.760 --> 00:24:16.920 Vamos a empezar al contrario. 406 00:24:16.920 --> 00:24:20.360 Si hay alguien de aquí, de los colegas, que quiera decir alguna cosa, 407 00:24:20.360 --> 00:24:25.440 que quiera hacer alguna pregunta, que se sienta libre de hacerla. Y 408 00:24:26.840 --> 00:24:29.760 bueno, y si no, pues vamos aquí a ver si 409 00:24:31.080 --> 00:24:35.480 la paz, presidente de socio, tiene algo que preguntar. 410 00:24:36.120 --> 00:24:40.240 Existe una? 411 00:24:40.680 --> 00:24:45.880 Si puedes ir a la diapositiva tres en un instante. 412 00:24:47.800 --> 00:24:48.120 Una vez. 413 00:24:48.120 --> 00:24:50.080 Donde esta? 414 00:24:50.080 --> 00:24:52.520 Parece haber un error. 415 00:24:53.600 --> 00:24:54.600 Ya se ha entendido. 416 00:24:54.600 --> 00:24:56.480 Perfecto. 417 00:24:56.480 --> 00:24:59.120 Pues es la siguiente. 418 00:24:59.120 --> 00:25:01.200 Donde tenías los resultados de micro dureza. 419 00:25:02.320 --> 00:25:04.640 Ah, vale. Es que me he perdido por. 420 00:25:04.640 --> 00:25:05.600 Por esto. 421 00:25:05.640 --> 00:25:06.640 La pregunta es. 422 00:25:06.640 --> 00:25:11.160 Por qué has usado micro dureza que tiene muy poca resolución espacial 423 00:25:11.520 --> 00:25:16.160 y no nano indentación, que para este caso hubiera tenido mucha más resolución. 424 00:25:17.360 --> 00:25:20.080 Y justo en la intercala, que es donde te interesa medir 425 00:25:20.880 --> 00:25:25.440 o hubieras podido tener una información mucho más clara. 426 00:25:26.360 --> 00:25:28.320 Y al final es que con toda la herramienta. 427 00:25:28.320 --> 00:25:34.520 De la que disponíamos, posiblemente hemos hecho tomas imágenes que yo digo 428 00:25:34.560 --> 00:25:39.760 en nuestro equipo de ventas y luego finalmente hicimos el análisis químico. 429 00:25:39.800 --> 00:25:44.640 Tomamos un método algo más preciso en el zoom, quizás para ver precisamente. 430 00:25:46.080 --> 00:25:48.760 Hacerte cerca del micrófono, porque si no, no se te oye. 431 00:25:49.120 --> 00:25:49.320 En las. 432 00:25:49.320 --> 00:25:52.920 Cosas que están fuera. No, de. Verdad, 433 00:25:53.000 --> 00:25:55.360 no se oye que 434 00:25:55.360 --> 00:25:59.360 hemos utilizado al final los métodos que tenemos un poco en la escuela 435 00:25:59.360 --> 00:26:03.600 y en el grupo y, ya sabes, lo hemos hecho lo mejor que hemos hecho. 436 00:26:03.600 --> 00:26:08.240 Una sugerencia del extranjero, porque posiblemente os de una información 437 00:26:08.680 --> 00:26:11.240 más precisa y complementaria a la que ya 438 00:26:11.280 --> 00:26:13.960 tenéis por imagen y por composición, que si 439 00:26:15.000 --> 00:26:15.400 mucho. 440 00:26:16.120 --> 00:26:20.680 A mi me pareció muy interesante el trabajo y has mencionado en varias ocasiones 441 00:26:20.680 --> 00:26:24.240 el tema de la resistencia a la corrosión, porque claro, aquí tú 442 00:26:24.240 --> 00:26:27.480 ves que tienes unos materiales que tienen tantas caras 443 00:26:28.520 --> 00:26:31.520 y de distintas composiciones, que luego cuando eso 444 00:26:31.520 --> 00:26:35.800 está operando en un sistema, habéis hecho alguna las medidas y no hemos. 445 00:26:35.800 --> 00:26:39.480 Llegado al final el TCM ha dado para los malo para lo que se ha contado. 446 00:26:39.840 --> 00:26:43.760 Evidentemente seguimos, tenemos que seguir más claro. 447 00:26:43.800 --> 00:26:47.800 Pues a ver si para la tesis puede dar muy buenos resultados. 448 00:26:48.280 --> 00:26:49.160 Enhorabuena, Juan. 449 00:26:49.160 --> 00:26:53.960 Vale, muchas gracias. 450 00:26:53.960 --> 00:26:56.600 Esfuerzos, full ingresos. 505 00:26:53.080 --> 00:26:56.720 hello everyone first of all I would like 506 00:26:55.159 --> 00:26:58.480 to thank the soci committee for 507 00:26:56.720 --> 00:27:00.640 selecting me as a fin finalist I'm very 508 00:26:58.480 --> 00:27:03.360 honored for that recognition as the 509 00:27:00.640 --> 00:27:05.440 chairman said I'm meono and today I'm 510 00:27:03.360 --> 00:27:07.039 talking about the master thesis I did 511 00:27:05.440 --> 00:27:09.760 last year at the University autonom 512 00:27:07.039 --> 00:27:10.840 Madrid under the supervision of Dr sharo 513 00:27:09.760 --> 00:27:13.440 and Dr 514 00:27:10.840 --> 00:27:15.960 miraya please don't be afraid of such a 515 00:27:13.440 --> 00:27:17.640 lar title what I'm explaining you today 516 00:27:15.960 --> 00:27:19.360 is how by a Noel stragedy we have 517 00:27:17.640 --> 00:27:21.679 already modeled and we are currently 518 00:27:19.360 --> 00:27:26.320 trying to reproduce experimentally we 519 00:27:21.679 --> 00:27:28.480 can dramatic dramatically um increase 520 00:27:26.320 --> 00:27:31.320 the performance of solar while reducing 521 00:27:28.480 --> 00:27:33.200 their cost I would like to start with a 522 00:27:31.320 --> 00:27:36.279 brief discussion of the energy situation 523 00:27:33.200 --> 00:27:37.919 in our worldall we are all familiarized 524 00:27:36.279 --> 00:27:40.480 with the need in our society to find a 525 00:27:37.919 --> 00:27:42.600 clean and renovable renovable source of 526 00:27:40.480 --> 00:27:44.640 energy here you have some a 527 00:27:42.600 --> 00:27:46.919 representation of the total war reserves 528 00:27:44.640 --> 00:27:49.679 of some non- renov renovable source of 529 00:27:46.919 --> 00:27:52.760 energy that as you know they are not 530 00:27:49.679 --> 00:27:54.519 only limit but also producing pollution 531 00:27:52.760 --> 00:27:58.039 problems and climate 532 00:27:54.519 --> 00:28:00.679 change nevertheless as per say 533 00:27:58.039 --> 00:28:03.120 earlier in only one year the solar 534 00:28:00.679 --> 00:28:05.679 energy that reach our planet is much 535 00:28:03.120 --> 00:28:09.039 higher than all that reserves together 536 00:28:05.679 --> 00:28:10.960 further more as you see here the cost of 537 00:28:09.039 --> 00:28:13.080 this non-renewable source of energy have 538 00:28:10.960 --> 00:28:16.519 been maintained over the years if not 539 00:28:13.080 --> 00:28:18.240 increased and on contrary solar 540 00:28:16.519 --> 00:28:19.760 photovolatic has gone from being the 541 00:28:18.240 --> 00:28:22.519 most expensive to the cheapest one in 542 00:28:19.760 --> 00:28:25.640 little more than a decade so what is our 543 00:28:22.519 --> 00:28:29.080 excuse here I mean we have the most 544 00:28:25.640 --> 00:28:31.279 powerful ER clean and cheap H source of 545 00:28:29.080 --> 00:28:34.159 energy at our disposal what is it what 546 00:28:31.279 --> 00:28:36.000 that we are not using it I personally 547 00:28:34.159 --> 00:28:38.320 don't know the answer to that question 548 00:28:36.000 --> 00:28:39.960 but as scientist the only thing we can 549 00:28:38.320 --> 00:28:42.640 do for the moment is continue improving 550 00:28:39.960 --> 00:28:44.640 even further this technology which is 551 00:28:42.640 --> 00:28:46.200 the main objective of the master thesis 552 00:28:44.640 --> 00:28:48.519 to do that we propose two different 553 00:28:46.200 --> 00:28:50.679 Pathways first of all the use of more 554 00:28:48.519 --> 00:28:53.240 accessible and cheaper materials and 555 00:28:50.679 --> 00:28:55.559 secondly increase efficiency of the 556 00:28:53.240 --> 00:28:56.799 devices regarding the first one we have 557 00:28:55.559 --> 00:28:59.519 to acknowledge the importance that 558 00:28:56.799 --> 00:29:01.240 silicon has in our society it has been 559 00:28:59.519 --> 00:29:04.960 the material used per excellence in 560 00:29:01.240 --> 00:29:08.039 almost every electronic technology as 561 00:29:04.960 --> 00:29:11.679 you see here the efficiency of these H 562 00:29:08.039 --> 00:29:13.799 silicon solar cells are ER for a long 563 00:29:11.679 --> 00:29:16.519 time now are optimal are near to the 564 00:29:13.799 --> 00:29:19.080 theoretical limit but the processing of 565 00:29:16.519 --> 00:29:21.640 this material requires thousand of 566 00:29:19.080 --> 00:29:23.519 degrees it is energetically expensive 567 00:29:21.640 --> 00:29:26.080 moreover it is controlled by Asian 568 00:29:23.519 --> 00:29:28.760 Powers so people rely on other countries 569 00:29:26.080 --> 00:29:31.159 to obtain it in this context Alli 570 00:29:28.760 --> 00:29:33.600 perides are very promising they have an 571 00:29:31.159 --> 00:29:36.399 octal structure where the vertices are 572 00:29:33.600 --> 00:29:38.480 Alli onion we have lead at the middle 573 00:29:36.399 --> 00:29:41.919 and we have an organic molecule or 574 00:29:38.480 --> 00:29:44.360 theion between octav the synthesis of 575 00:29:41.919 --> 00:29:46.360 this material is much easier and only 576 00:29:44.360 --> 00:29:49.120 requires 577 00:29:46.360 --> 00:29:51.000 100° furthermore depending on their 578 00:29:49.120 --> 00:29:53.120 composition we can obtain different oo 579 00:29:51.000 --> 00:29:55.640 electronic properties as you see here 580 00:29:53.120 --> 00:29:57.960 band gaps over a wide range can be 581 00:29:55.640 --> 00:30:01.320 obtained so the Great properties of 582 00:29:57.960 --> 00:30:04.279 these materials have lead to an increase 583 00:30:01.320 --> 00:30:06.320 in the an increase in the evolution of 584 00:30:04.279 --> 00:30:10.159 the deficiency of pery 585 00:30:06.320 --> 00:30:12.080 solar incredible and a little more than 586 00:30:10.159 --> 00:30:15.559 a decade they are also at the level 587 00:30:12.080 --> 00:30:17.320 there are all there are and already at 588 00:30:15.559 --> 00:30:20.279 the level of 589 00:30:17.320 --> 00:30:23.600 silicon so okay now let's see the second 590 00:30:20.279 --> 00:30:25.399 approach to see how uh to increase the 591 00:30:23.600 --> 00:30:27.440 efficiency of the device I will start 592 00:30:25.399 --> 00:30:30.120 with the basic with the fundamentals of 593 00:30:27.440 --> 00:30:32.399 solar cell here you have a general 594 00:30:30.120 --> 00:30:34.799 schematic of a solar cell where we have 595 00:30:32.399 --> 00:30:36.440 a semiconductor as the absorbing layer 596 00:30:34.799 --> 00:30:38.720 and then we have a few other layers that 597 00:30:36.440 --> 00:30:41.360 ensure the operation of the cell let's 598 00:30:38.720 --> 00:30:43.480 illuminate it from above look at that 599 00:30:41.360 --> 00:30:45.640 Photon that is coming back coming down 600 00:30:43.480 --> 00:30:48.039 to be absorbed at the semiconductor 601 00:30:45.640 --> 00:30:50.480 suppose that that Photon has an energy 602 00:30:48.039 --> 00:30:52.799 quite higher than that of the bangard an 603 00:30:50.480 --> 00:30:56.240 electron from the conduction from the 604 00:30:52.799 --> 00:30:59.240 balance band will be well the animations 605 00:30:56.240 --> 00:30:59.240 are 606 00:31:00.039 --> 00:31:03.840 okay an electron is going to be promoted 607 00:31:02.360 --> 00:31:06.600 from the balance band to the condution 608 00:31:03.840 --> 00:31:09.760 band with that excess of energy but due 609 00:31:06.600 --> 00:31:12.080 to the low the low the less energetic 610 00:31:09.760 --> 00:31:14.279 State inside the vs this charge will 611 00:31:12.080 --> 00:31:15.919 thermalize eventually to the band EDS 612 00:31:14.279 --> 00:31:18.000 losing that excess of energy at the 613 00:31:15.919 --> 00:31:20.840 moment of the charge struction so as you 614 00:31:18.000 --> 00:31:24.519 see these thermalization losses are 615 00:31:20.840 --> 00:31:26.440 reducing dramatically the possible the 616 00:31:24.519 --> 00:31:28.760 potential efficiency of a solar cell 617 00:31:26.440 --> 00:31:31.120 leaving a the IAL limit at only 618 00:31:28.760 --> 00:31:33.240 33% one could say that in order to 619 00:31:31.120 --> 00:31:35.360 mitigate these thermalization losses we 620 00:31:33.240 --> 00:31:38.240 should increase the band gap of the 621 00:31:35.360 --> 00:31:40.200 semiconductor to extract the the charge 622 00:31:38.240 --> 00:31:42.679 the charges at higher potential but if 623 00:31:40.200 --> 00:31:44.480 we do that if we increase the the energy 624 00:31:42.679 --> 00:31:46.720 of the bandup less photons from the 625 00:31:44.480 --> 00:31:49.799 incoming solar Spectrum will be absorbed 626 00:31:46.720 --> 00:31:52.320 so we will generate less current and 627 00:31:49.799 --> 00:31:54.480 this is H where the standing config 628 00:31:52.320 --> 00:31:56.000 configuration comes into play here we 629 00:31:54.480 --> 00:31:57.799 have two sub cells one on top of the 630 00:31:56.000 --> 00:31:59.840 other made of different materials that 631 00:31:57.799 --> 00:32:03.159 will absorb different spectral regions 632 00:31:59.840 --> 00:32:04.720 we first we first have a white B bang 633 00:32:03.159 --> 00:32:06.320 semiconductor that will absorb the most 634 00:32:04.720 --> 00:32:08.720 energetic photons leading to 635 00:32:06.320 --> 00:32:10.360 thermalization to higher potentials and 636 00:32:08.720 --> 00:32:12.000 then we will have the narrow bandas 637 00:32:10.360 --> 00:32:15.000 semiconductor that will absorb the 638 00:32:12.000 --> 00:32:17.000 remaining less energetic photons in this 639 00:32:15.000 --> 00:32:19.480 H configuration we have to think into 640 00:32:17.000 --> 00:32:20.760 account that the both two cells one on 641 00:32:19.480 --> 00:32:23.080 top of the other are connected in 642 00:32:20.760 --> 00:32:25.559 serious so the total voltage of the cell 643 00:32:23.080 --> 00:32:27.760 will be the sum of both voltages while 644 00:32:25.559 --> 00:32:29.080 the current will be limited 645 00:32:27.760 --> 00:32:30.960 by that subcell that produce l 646 00:32:29.080 --> 00:32:33.720 photocurrent so we will need to find 647 00:32:30.960 --> 00:32:36.120 what is known as current matching 648 00:32:33.720 --> 00:32:37.600 conditions it is that is to make both 649 00:32:36.120 --> 00:32:39.679 sub cells to absorb the same amount of 650 00:32:37.600 --> 00:32:40.760 like in order to maximize the total 651 00:32:39.679 --> 00:32:44.120 current 652 00:32:40.760 --> 00:32:47.240 cell if we fulfill that an a new 653 00:32:44.120 --> 00:32:49.960 theoretical limit open open UPS to 654 00:32:47.240 --> 00:32:51.399 44% so as I told you before one of the 655 00:32:49.960 --> 00:32:55.320 most attractive properties of allight 656 00:32:51.399 --> 00:32:58.039 perides is the the Bon ability depending 657 00:32:55.320 --> 00:33:00.919 on their composition so we have all this 658 00:32:58.039 --> 00:33:04.120 composition suitable for a White Band 659 00:33:00.919 --> 00:33:05.919 Gap layer in a tund and luckily a few 660 00:33:04.120 --> 00:33:08.240 years ago some members of my group and 661 00:33:05.919 --> 00:33:10.919 others demonstrated that by a partial 662 00:33:08.240 --> 00:33:14.000 substituting of lead by team narrow bang 663 00:33:10.919 --> 00:33:18.000 AOS skite will also possible opening the 664 00:33:14.000 --> 00:33:18.000 possibility of all peros Sky tund solar 665 00:33:18.360 --> 00:33:23.720 cells okay H the problem this material 666 00:33:21.279 --> 00:33:25.760 have the steam light lead perite is that 667 00:33:23.720 --> 00:33:27.840 they do not absorb as efficiently as the 668 00:33:25.760 --> 00:33:30.880 previous composition so it's going to be 669 00:33:27.840 --> 00:33:32.960 the limiting factor in a tund device the 670 00:33:30.880 --> 00:33:35.440 problem the the solution we propose to 671 00:33:32.960 --> 00:33:37.320 WorkOne this problem is the use of 672 00:33:35.440 --> 00:33:39.559 metallic nanop particles that support 673 00:33:37.320 --> 00:33:40.799 localized surface plasmonic resonances 674 00:33:39.559 --> 00:33:44.320 as the one you are seeing in the 675 00:33:40.799 --> 00:33:46.679 simulation with these particles we can 676 00:33:44.320 --> 00:33:49.080 surgically increase the electric field 677 00:33:46.679 --> 00:33:51.399 at the exact position and at the exact 678 00:33:49.080 --> 00:33:54.039 spectral region we want so by means of 679 00:33:51.399 --> 00:33:56.399 introducing this nanop particles inside 680 00:33:54.039 --> 00:33:59.080 the narrow banga perite we can increase 681 00:33:56.399 --> 00:34:00.960 its absortion so basically we are like 682 00:33:59.080 --> 00:34:02.760 doctors operating a solar cell to 683 00:34:00.960 --> 00:34:05.399 increase its 684 00:34:02.760 --> 00:34:08.399 absorption so we did the simulations 685 00:34:05.399 --> 00:34:10.399 using the fdtd method at first not in a 686 00:34:08.399 --> 00:34:12.440 tment but in a single Junction model as 687 00:34:10.399 --> 00:34:13.879 the one you are seeing here and we 688 00:34:12.440 --> 00:34:16.359 optimize several 689 00:34:13.879 --> 00:34:19.040 parameters the particle material between 690 00:34:16.359 --> 00:34:21.440 copper gold and silver the radius of the 691 00:34:19.040 --> 00:34:23.359 Spheres and the volume concentration 692 00:34:21.440 --> 00:34:25.839 that we introduce those SPS inside the 693 00:34:23.359 --> 00:34:28.320 peros skite and we obtain these results 694 00:34:25.839 --> 00:34:30.560 for the uh the current 695 00:34:28.320 --> 00:34:33.079 calculated for different sizes and 696 00:34:30.560 --> 00:34:36.000 concentration obtaining this optimal 697 00:34:33.079 --> 00:34:38.200 case for this silver Nano particles 698 00:34:36.000 --> 00:34:40.760 let's analyze it in more detail here you 699 00:34:38.200 --> 00:34:43.960 have the absor and spectrum of that 700 00:34:40.760 --> 00:34:46.159 optimal case represented in Orange in 701 00:34:43.960 --> 00:34:47.919 compared to that of a reference cell 702 00:34:46.159 --> 00:34:50.599 without using nanop particles and as you 703 00:34:47.919 --> 00:34:53.839 can see there's a a considerable 704 00:34:50.599 --> 00:34:55.879 Improvement specifically at long 705 00:34:53.839 --> 00:34:58.000 wavelength now what you are seeing is 706 00:34:55.879 --> 00:35:01.440 the differential absortion 707 00:34:58.000 --> 00:35:03.280 per per unit of volume at different at 708 00:35:01.440 --> 00:35:05.960 crossing your planes at different wave 709 00:35:03.280 --> 00:35:07.920 of interest at your right we have the 710 00:35:05.960 --> 00:35:10.359 reference cell where we can see this 711 00:35:07.920 --> 00:35:13.320 fabrio type interference typically in a 712 00:35:10.359 --> 00:35:16.320 Plano paral multier structure and at the 713 00:35:13.320 --> 00:35:18.240 plasmonic cell we can see this multi 714 00:35:16.320 --> 00:35:20.839 multi multipolar plasmonic resonance 715 00:35:18.240 --> 00:35:22.599 coming from the nanop particle so from 716 00:35:20.839 --> 00:35:24.599 these figures we can deduce that the 717 00:35:22.599 --> 00:35:27.599 absortion enhancement comes from a fine 718 00:35:24.599 --> 00:35:29.920 coupling between both effects which is 719 00:35:27.599 --> 00:35:31.160 what we have been optimizing during the 720 00:35:29.920 --> 00:35:33.400 the 721 00:35:31.160 --> 00:35:34.720 simulation and finally we went for a 722 00:35:33.400 --> 00:35:37.079 Tandon 723 00:35:34.720 --> 00:35:39.520 device we did the same 724 00:35:37.079 --> 00:35:41.480 optimizations in a model as the one you 725 00:35:39.520 --> 00:35:43.480 are seeing but this time using as a 726 00:35:41.480 --> 00:35:45.240 starting point the optimal nanop 727 00:35:43.480 --> 00:35:47.880 particles previously calculated for the 728 00:35:45.240 --> 00:35:49.520 single Junction solar cell and we 729 00:35:47.880 --> 00:35:53.160 obtaining the result for the match 730 00:35:49.520 --> 00:35:54.720 current finding this optimal case as I 731 00:35:53.160 --> 00:35:56.640 told you before due to the series 732 00:35:54.720 --> 00:35:58.319 connection of both two cells in a tandem 733 00:35:56.640 --> 00:36:00.839 we we have had to calculate the current 734 00:35:58.319 --> 00:36:03.640 matching conditions in every Point 735 00:36:00.839 --> 00:36:06.000 here and as an example of that is what 736 00:36:03.640 --> 00:36:08.200 you are seeing here as we increase the 737 00:36:06.000 --> 00:36:10.359 front peros Sky thickness more photons 738 00:36:08.200 --> 00:36:13.040 will be absorbed there so the current in 739 00:36:10.359 --> 00:36:15.599 the front suell will be increased as you 740 00:36:13.040 --> 00:36:17.720 see represented in green on contrary 741 00:36:15.599 --> 00:36:20.400 less photons will reach the r Sur cell 742 00:36:17.720 --> 00:36:22.040 so the current there will be decreased 743 00:36:20.400 --> 00:36:24.040 and that's going to be a point at which 744 00:36:22.040 --> 00:36:26.400 both currents will match with each other 745 00:36:24.040 --> 00:36:27.560 maximizing the total current of the cell 746 00:36:26.400 --> 00:36:31.640 and that 747 00:36:27.560 --> 00:36:36.240 happens at 1536 for a red fa and Cel 748 00:36:31.640 --> 00:36:38.480 represented in Orange and at 1637 for a 749 00:36:36.240 --> 00:36:40.400 for the optimal plasmonic tanden cell 750 00:36:38.480 --> 00:36:42.880 represented in blue and this current 751 00:36:40.400 --> 00:36:45.400 enhancement corresponds to more than a 752 00:36:42.880 --> 00:36:48.760 super and absolute efficiency 753 00:36:45.400 --> 00:36:51.200 enhancement so I have I I hope that I 754 00:36:48.760 --> 00:36:52.880 have convinced you that um using 755 00:36:51.200 --> 00:36:54.640 designing solar cells using more 756 00:36:52.880 --> 00:36:57.240 affordable material is the path for the 757 00:36:54.640 --> 00:37:00.160 future and for that reason we have 758 00:36:57.240 --> 00:37:02.920 modelized all per Sky T solar set using 759 00:37:00.160 --> 00:37:06.560 nanop particles to overcome their 760 00:37:02.920 --> 00:37:09.800 limitations we found a system that 761 00:37:06.560 --> 00:37:12.240 promise an absolute 2% efficiency 762 00:37:09.800 --> 00:37:14.520 enhancment and to finish just say that 763 00:37:12.240 --> 00:37:18.200 the experimental demonstration of these 764 00:37:14.520 --> 00:37:20.560 uh models is already in progress I'm in 765 00:37:18.200 --> 00:37:23.640 contact with yunhan at the University of 766 00:37:20.560 --> 00:37:25.400 of Cambridge who is already making this 767 00:37:23.640 --> 00:37:27.240 device this old peros skan and solar 768 00:37:25.400 --> 00:37:29.200 cell the s 769 00:37:27.240 --> 00:37:31.079 of the of the nanop particles have 770 00:37:29.200 --> 00:37:34.119 already begun and first attempt to 771 00:37:31.079 --> 00:37:38.560 include this in the solar cells have 772 00:37:34.119 --> 00:37:40.960 also been made and thank you all of you 773 00:37:38.560 --> 00:37:44.079 for your your attention and thank to all 774 00:37:40.960 --> 00:37:46.280 my group for their support thank you 775 00:37:44.079 --> 00:37:46.280 very 776 00:37:55.599 --> 00:37:58.599 much 629 00:37:49.400 --> 00:37:51.880 Bueno, pues nada Jaime, que 630 00:37:52.680 --> 00:37:55.840 la verdad es que es una faena, que los tres sois tan buenos. 631 00:37:56.840 --> 00:37:58.920 Es muy bueno para la ciencia, pero muy malo 632 00:37:59.680 --> 00:38:02.400 para esos demás que solo tiene un premio. 633 00:38:02.400 --> 00:38:05.680 Aunque yo creo que habría que hablar con el presidente para que el año que viene 634 00:38:05.960 --> 00:38:08.760 haya más premios, porque es que de verdad es una pasada. 635 00:38:09.000 --> 00:38:12.480 Los tres que habéis presentado y no sé si alguien en la sala quiere. 636 00:38:13.160 --> 00:38:14.560 Por favor, profesor. 637 00:38:14.560 --> 00:38:17.960 Yo hice tu. 638 00:38:17.960 --> 00:38:18.760 Sí, yo. 639 00:38:18.760 --> 00:38:21.480 Yo tengo una pregunta de 640 00:38:22.280 --> 00:38:24.120 ese hombre sobre el material. 641 00:38:24.120 --> 00:38:29.040 A mi me encantan las rosquillas de plomo, pero como todo, como nos llevamos 642 00:38:29.040 --> 00:38:33.120 con la normativa europea de no usar plomo, porque en otro tipo de. 643 00:38:33.120 --> 00:38:35.160 Dispositivos en los que yo uso proscritas, 644 00:38:35.160 --> 00:38:38.960 estamos obligados a suprimir el plomo en todas ellas. 645 00:38:39.960 --> 00:38:41.640 Efectivamente, el plomo, la 646 00:38:41.640 --> 00:38:45.360 toxicidad del programa es un claro problema actualmente. 647 00:38:45.840 --> 00:38:49.040 Pero fíjate que esta aproximación que nosotros estamos tomando 648 00:38:49.720 --> 00:38:51.360 va en la línea de reducir. 649 00:38:51.360 --> 00:38:55.200 Aparte de que los grosores ya de por sí son bastante límite, 650 00:38:56.040 --> 00:38:59.200 son muy finos estas capas, entonces el contenido de plomo 651 00:38:59.200 --> 00:39:03.880 es bastante escaso y todo este dispositivo llevaría un encapsulado 652 00:39:03.880 --> 00:39:05.520 para tratar de que no haya fugas. 653 00:39:05.520 --> 00:39:08.880 Pero aparte de eso, toda esta aproximación se trata de aumentar 654 00:39:08.880 --> 00:39:13.680 la absorción del material para reducir la incluso más, incluso las. 655 00:39:13.680 --> 00:39:16.360 Pero ten en cuenta que las velocidades de las que estamos hablando 656 00:39:17.040 --> 00:39:20.000 son estas que sustituimos el plomo por el estaño. 657 00:39:20.040 --> 00:39:23.880 En el caso la tandem es verdad que la de arriba seguiría teniendo plomo, pero 658 00:39:24.480 --> 00:39:29.280 y la línea del trabajo es intentar un poco reducir ese contenido en plomo 659 00:39:30.240 --> 00:39:32.480 en sentidos, tanto en la composición de la pelotita 660 00:39:32.480 --> 00:39:35.160 como en el grosor de la velocidad. 661 00:39:35.560 --> 00:39:37.840 Pero sí es verdad que el plomo es 662 00:39:37.840 --> 00:39:40.880 una de las cosas que más echan atrás actualmente a las florecitas. 663 00:39:41.880 --> 00:39:44.560 Bueno, gracias 664 00:39:44.560 --> 00:39:46.640 Paloma, que desahogo. 665 00:39:46.640 --> 00:39:50.520 No, la verdad es que lo suscribo y muy bien para 666 00:39:51.080 --> 00:39:53.960 la ciencia y futuro de la ciencia, pero muy mal 667 00:39:54.520 --> 00:39:58.640 de nuestro tiempo por dentro, en un pais en un aprieto. 668 00:39:58.960 --> 00:40:01.960 Pero bueno, muchas ni eso. 669 00:40:02.280 --> 00:40:05.040 Solamente añadir que es la diversidad de campos 670 00:40:05.040 --> 00:40:08.520 en los cuales se trabaja, lo cual es muy de agradecer. 671 00:40:08.880 --> 00:40:11.440 Quiere decir que nuestra ciencia 672 00:40:11.440 --> 00:40:13.200 es muy ancha y eso es muy bueno. 673 00:40:13.200 --> 00:40:14.400 Muchas gracias. 674 00:40:14.480 --> 00:40:16.800 Bueno, pues muchas gracias. 675 00:40:17.400 --> 00:40:20.960 Ahora la profesora Paloma Fernández y el profesor José Ignacio Pastor 676 00:40:21.280 --> 00:40:25.120 van a hacer entrega, que yo llamaría a los tres finalistas para que vengan 677 00:40:25.120 --> 00:40:27.120 aquí. 678 00:40:30.840 --> 00:40:33.440 Muchas gracias, Sandra. 679 00:40:33.480 --> 00:40:41.520 Buenas. 680 00:40:45.960 --> 00:40:50.760 Bueno, eso ocurrió. 681 00:40:50.760 --> 00:40:52.920 No todos son prosélitos. 682 00:40:52.960 --> 00:40:58.160 Si, bueno, 683 00:40:59.880 --> 00:41:00.560 improviso. 684 00:41:00.560 --> 00:41:02.400 Pues no se improvisa. 685 00:41:02.400 --> 00:41:07.640 No? Para mí es una placer estar aquí. 686 00:41:08.040 --> 00:41:10.840 Bueno, además, como todo en este año, 687 00:41:10.840 --> 00:41:13.800 está siendo un poco la primera vez después de la pandemia. 688 00:41:14.000 --> 00:41:14.880 Por fin. 689 00:41:15.120 --> 00:41:17.640 Entonces, la verdad es que es un placer, porque me he vuelto a encontrar 690 00:41:17.640 --> 00:41:19.800 con gente con la que quiero mucho. 691 00:41:19.800 --> 00:41:23.080 Creo que con la lleva un montón de tiempo sin podernos encontrar a todos. 692 00:41:23.080 --> 00:41:25.760 Es un placer. Es un placer además, ver como las cosas que 693 00:41:27.040 --> 00:41:29.280 nació hace unos cuantos años, 694 00:41:29.760 --> 00:41:33.480 pues con esfuerzo pero casi como venga José Ignacio, 695 00:41:33.480 --> 00:41:38.880 tu pones unas fotos allí en la escuela y simultáneamente yo pongo otras fotos 696 00:41:38.880 --> 00:41:43.880 aquí en el pasillo de mi facultad y hacemos un concurso en Twitter 697 00:41:44.240 --> 00:41:47.040 y hacemos algo para dar, para celebrar, para apuntarnos. 698 00:41:47.880 --> 00:41:48.960 Bien y tu y no. 699 00:41:48.960 --> 00:41:50.760 Te vayas en 30. 700 00:41:50.760 --> 00:41:52.960 Minutos, vamos ya muy viejos. 701 00:41:53.400 --> 00:41:57.080 Pues es un placer ver como aquello que bueno es que fue literalmente 702 00:41:57.360 --> 00:42:00.240 dos exposiciones simultáneas, una en la facultad de pases 703 00:42:00.240 --> 00:42:04.600 de la Facultad de Física de la Complutense y otra en el pasillo de esta facultad, 704 00:42:05.240 --> 00:42:08.280 y que de ahí ya hemos llevado hasta aquí. 705 00:42:08.720 --> 00:42:11.760 Entonces eso me parece que es 706 00:42:11.760 --> 00:42:12.160 bueno. 707 00:42:12.320 --> 00:42:15.560 Una cosa por la que nos tenemos que felicitar todos y que desde luego, 708 00:42:15.560 --> 00:42:18.240 pues me hace sentirme muy feliz. 709 00:42:18.840 --> 00:42:22.720 Y la única faena pues que eso es demasiado bueno. 710 00:42:22.840 --> 00:42:25.920 Y entonces pues como soy demasiado bueno nos lo ponen muy difícil 711 00:42:26.360 --> 00:42:29.160 a la hora de decidir estas cosas, 712 00:42:29.160 --> 00:42:31.680 porque habría que daros un premio a todos. 713 00:42:32.400 --> 00:42:35.560 Saben que está muy bien, porque bueno, cuando algunos ya llevábamos 714 00:42:35.560 --> 00:42:39.000 un poquito retirada, pues vemos que las nuevas generaciones 715 00:42:39.400 --> 00:42:41.520 verdaderamente prometen 716 00:42:42.080 --> 00:42:45.600 y eso está muy bien y en parte. 717 00:42:46.600 --> 00:42:48.720 No nada más felicitaros a los tres. 718 00:42:49.000 --> 00:42:51.720 Ahora, si el ganador tiene 719 00:42:51.720 --> 00:42:54.600 la responsabilidad de ganar 720 00:42:55.320 --> 00:42:58.800 el concurso europeo, o sea que 721 00:42:58.800 --> 00:43:00.720 tiene una responsabilidad 722 00:43:00.720 --> 00:43:04.880 enorme detrás de él porque va a representar a toda su madre 723 00:43:05.840 --> 00:43:10.520 en una competición europea al Mundial realmente del más alto nivel. 724 00:43:10.640 --> 00:43:14.520 Enhorabuena de nuevo a vosotros y a vuestros directores de los trabajos. 725 00:43:14.520 --> 00:43:16.680 Esos serán el lunes normal que nos veremos de nuevo. 726 00:43:18.400 --> 00:43:20.760 Bueno, pues empezamos por los finalistas. 727 00:43:21.360 --> 00:43:24.240 Los finalistas son aves blancas y todo esto. 728 00:43:24.720 --> 00:43:27.480 Juan Jiménez a Lumbreras 729 00:43:36.320 --> 00:43:39.360 y Jaime Bueno, Benito 730 00:43:44.440 --> 00:43:46.520 y bueno, ya tiene menos emoción. 731 00:43:46.520 --> 00:43:49.560 Claro, el ganador en ese caso, bueno, tendrá 732 00:43:51.360 --> 00:44:01.600 mi enhorabuena.