Chapter 363: Landmark breakthrough

After the small organic photovoltaic meeting was over, everyone started to work.
In the inner laboratory, Tian Qing is preparing the solution, Mo Wenlin and Han Jiaying are testing the device, outside the office, Chen Wanqing and Wu Shengnan code words at the desk.
Xu Qiu stayed in the office, and first fitted the test results of the exciton diffusion distance in the previous two days to the results of the simulation laboratory, that is, the results of ITIC and IDIC were 13.0 nanometers and 19.2 nanometers respectively. Now that I know it has been repeated many times He did not intend to let Tian Qing test the results of fitting under the data again in reality.
After all, these two final results are all fitted by about 500 data in the simulation laboratory, which adds up to 1000 data. If you test it again in reality, it will take at least ten days.
In fact, they are unwilling to carry out repetitive experiments. This is also the idea of ​​many research groups in China.
The domestic large group is okay. In the case of a small group, basically repetitive experiments can be carried out according to the lowest standard, and the lowest standard will be followed.
For example, in organic photovoltaics, many groups use the conditions of "5 batches of devices with more than 20 device points", including Xu Qiu when he first started.
Now, Xu Qiu’s optimal system usually adopts the conditions of
10 batches and more than 50 device points
, and will also send samples to NIM for third-party testing, and the data reliability is much higher.
For foreigners doing experiments, repetitive experiments generally exceed the minimum standard a lot, and the stability of the data and the length of the error bars are relatively short.
This also leads to a problem of judging paper fraud. If it is because the repetition of one's own experiment is not high enough, and other people cannot repeat it, how should this be judged?
You said he didn't make a fake, this result really cannot be repeated.
But you say he made a fake, this result was measured at that time, and there is no trace of artificial modification.
It's hard to judge.
This is why the publication of high-quality articles now pays more and more attention to third-party testing.
It's true or false, and you can tell at a glance.
After that, Xu Qiu and Xu Qiu sent an email to the teacher in charge of allocating the time of the light source, applying for the GIWAXS scheduling of September and the emergency time of the R-SoXS test.
In the e-mail, he blew a wave of his work, "It is expected to be published in the major journal of Nature. It is very urgent. The article is almost finished. Now the light source data is missing."
Although the article has not actually started to be written, and even the experimental characterization data is still more than a dozen to be completed, it is still necessary to blow a wave when it is time to blow, otherwise, how can it be done?
After finishing these two items, Xu Qiu heard cheers from the school girl and Mo Wenlin from the direction of the laboratory: "The efficiency has exceeded 13%!"
Xu Qiu heard the sound and walked into the inner laboratory.
"Brother, the highest efficiency is 13.11%~" Han Jiaying said happily with a smile on her face.
Then she added another sentence: "The test is the J2: IDIC-4F system, and the area of ​​the shield is 0.01 square centimeters."
The organic photovoltaic field has maintained an efficiency of 12% for nearly four years. Today, it was successfully broken by a school girl and stepped up a step, reaching 13%, and the J2 donor material was synthesized by her personally. She is not excited. It.
"Yes, not bad." Xu Qiu encouraged and patted the schoolgirl on the shoulder, then looked at the J-V curve on the computer.
The J-V curve is flat and then rises. It is very standard. The photoelectric parameters next to it are 13.11% efficiency, open circuit voltage 0.93 volts, short circuit current density 19.58 mA per square centimeter, and fill factor is very high, reaching 0.72.
'The filling factor is very high...' Xu ​​Qiu thought about the results of the exciton diffusion distance tested before, and came up with an idea to explain this phenomenon: "The IDIC system has a long exciton diffusion distance and can prepare thick Films and large-size devices indicate that they have a high tolerance for the morphology of the effective layer film, which is beneficial to increase the fill factor."
In the field of organic photovoltaics, the open circuit voltage is directly related to the forbidden band width, and the short-circuit current is directly related to the light absorption range and indirectly related to the forbidden band width. The fill factor is a comprehensive standard and is mainly affected by the morphology of the effective layer.
Here, Xu Qiu connects the exciton diffusion distance and the fill factor together. It is a point of view he put forward to explain this experimental phenomenon to each other. It is not a proof in the strict sense. The point of view may be correct or wrong, but whether it is correct or No, as long as you can justify yourself, every new point of view can add points to the article.
In the case of non-big guys irrigating water, if you want to break through the barriers of AM, JACS and other top publications, and reach the "Nature" major journal or CNS main journal, it depends on the accumulation of bit by bit in the article. At this point, it is difficult to use the method of irrigating periodicals in the first and second districts with the previous template.
Han Jiaying saw that Xu Qiu only commented on a couple of "good" and then she lost her voice. She couldn't help turning her head and saying, "Brother, you are so calm. This is 13%... Yes, you have already predicted this before. It turned out."
"Student girls continue to test, maybe the IDIC-M system is more efficient." Xu Qiu smiled and changed the subject, without explaining that the reason for his calmness was that he had been excited once during the previous summer vacation. The value in the laboratory is higher than it is now, reaching 13.52%.
"Oh, the IDIC-M system has been tested, and the highest efficiency is only 12.89%." Han Jiaying said fortunately: "I thought I couldn't go up to 13% today, but I was surprised when I looked back."
I chatted with the school girls and others. Xu Qiu left the laboratory and went to 218. High efficiency was the biggest highlight of this job. He decided to tell Wei Xingsi of the news and at the same time communicate with Teacher Wei about what articles to contribute to this job.
When Xu Qiu entered room 218, he found Wei Xingsi was making a call.
Teacher Wei's expression changed a bit, and he said with emotion: "Said Cao Cao will be there when Cao Cao is there, Yuan Jiang, Xu Qiu just happened to be here, let me ask him."
While speaking, he turned on the speakerphone, and Gong Yuanjiang's voice came from the speaker: "Okay."
Wei Xingsi asked Xu Qiu: "Gong Yuanjiang and the others said that a batch of ITIC is needed. How much ITIC do we have now? Is there 200 mg?"
Xu Qiu thought about it, and replied: "200 mg should be available."
ITIC belongs to the standard system. As a standard system, it means that each donor material is combined. First, it must be combined with ITIC to make a batch of devices as a standard for comparison.
Therefore, Xu Qiu had asked Wu Shengnan to synthesize more than 2 grams of ITIC at one time, and now there is more than 1 gram left to be used, and the distribution of 200 mg did not have much impact on the research team.
Xu Qiu probably understands Gong Yuanjiang's intention to seize the opportunity. The faster the work is completed, the higher the chance of publishing a good article.
At the same time, Xu Qiu also had to say that Gong Yuanjiang’s actions were quite fast. In the JACS that he published before on AM and the school girl, both ITIC systems have just been proof (verification) completed. After searching online, Gong Yuanjiang appeared.
200 milligrams of ITIC should be enough for Gong Yuanjiang to prepare devices for one or two months. After one or two months, they will definitely be able to synthesize ITIC independently. After all, they have imitated and developed the ADA receptor material derived from the ICIN unit. Now only need to synthesize the central IDTT, and there are ready-made documents for reference.
Once the large research group starts at full speed, the research and development capabilities cannot be underestimated.
However, they must have never expected that Xu Qiu's materials have been iterated for several generations:
Narrow band gap ADA acceptor materials include IT-4F, IDIC, IDIC-4F, etc.; donor materials also range from H22 to H43, and then to J1, J2; near-infrared acceptor materials, including school sister's, -4F,- 4Cl, and the FN-4F of the post-doctorate sister.
The efficiency data has also broken through from 10%, 11%, and 12% step by step to the current 13%.
It takes at least half a year or even more than a year for Gong Yuanjiang to catch up with Xu Qiu's progress.
Wei Xingsi: "Then Xu Qiu tomorrow, you ask Mo Wenlin to send 200 mg ITIC to Yuanjiang and the others."
Gong Yuanjiang: "Okay, thank you. Xu Qiu should have something to do with you, I won't bother you much, bye."
Wei Xingsi: "Don't be polite with me, goodbye."
After hanging up the phone, Wei Xingsi smiled and said to Xu Qiu: "ITIC's influence is still relatively high. Since the proof of your two articles a few days ago, I have recently received emails from several domestic research groups. , Ask us about ITIC."
Xu Qiu gave an "um", and Wei Xingsi asked casually: "By the way, what is it that you came to find me?"
"Just tested the device, the efficiency exceeded 13%." Xu Qiu responded.
"13%?!" Wei Xingsi originally wanted to put the mobile phone on the wireless charger, but one could not hold it firmly. The mobile phone slipped and fell to the ground. Fortunately, there was a carpet cushion underneath and the mobile phone was fine.
Xu Qiu watched the funny look of Teacher Wei bending over to pick up the phone, and while holding a smile, he explained: "Yes, the specific value is 13.11%, J2: IDIC-4F system."
"13%, 13%..." Wei Xingsi didn't see Xu Qiu's weirdness. He couldn't help but repeat his emotions. Later, he even closed his eyes and breathed deeply, calming his mood. In the same way, when he suddenly received a surprise, the blood rushed to his forehead.
For Xu Qiu and Han Jiaying, this data is actually not that deep. After all, they have been in the industry for more than a year after they have been in the industry, and they have always been smooth. They have not had that kind of hold for half a year or a year. No experience of improvement at work.
But for Wei Xingsi, a researcher who has been doing photovoltaics for a small half of his life, the ups and downs are of great significance. It also made him feel a lot~EbookFREE.me~ I didn't expect that his research team could reach this point.
The breakthrough in efficiency from 12% to 13% can be regarded as a milestone event in the field of organic photovoltaics.
This indicates that the non-fullerene system has been far behind from the initial stage to the equivalent level before, and now it has achieved a comprehensive surpassing of the fullerene system.
At the same time, this progress will definitely be listed on NREL's "Highest Solar Cell Device Efficiency Map" after being certified by a third-party testing agency.
NREL is the National Renewable Energy Laboratory in a beautiful country. It will update the world record of various solar cell efficiency at regular intervals. Once it is listed, it will permanently become a point on the line chart and indicate the world. The work unit of the person who created the record.
Before returning to China, Wei Xingsi worked under a big boss in NREL, but he was mainly engaged in PDI, and the highest efficiency value was only 5% and 6%. He usually watched other big bosses' names hanging on it.
Today, Wei Xingsi finally got his chance.
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