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.