I Have a Research Support System

On January 28, the writing of Xu Qiu's summary proposal was coming to an end.

He has already integrated the third part of the content that Chen Wanqing is in charge of into the plan, and now only the prospect part is left.

This year's Spring Festival is on February 6th, and the research group's holiday time is from January 31st to February 13th.

Therefore, they had to submit this proposal to Mr. Wei before the research group's holiday, and Mr. Wei would be responsible for contacting the editor afterwards.

In the afternoon, Xu Qiu and Chen Wanqing sat at their desks and started discussing the "Prospect" part of the review.

At the same time, they also called Han Jiaying to listen in. The school girl mainly acted as an audience and recorded their discussions.

"I think before discussing the prospect, we can first discuss the direction we plan to do next." Xu Qiu suggested.

"Yes, um..." Chen Wanqing thought for a moment, and said, "Those unsystematic molecular structures, that is, other classifications in the review, can be excluded first, then choose from the three mainstream directions, junior, you Any thoughts?"

"I think the N2200 series can be ruled out first among the remaining three systems." Xu Qiu said without hesitation: "In the field of organic photovoltaics, long-term research experience has shown that there are two materials, the donor and the acceptor, and one is the polymer. The other choice is small molecules, the optoelectronic performance of this combination is better.

The theoretical basis is that from the perspective of morphology, such a polymer/small molecule combination is easier to form a bicontinuous interpenetrating network structure, that is, a three-phase structure.

At this stage, I think we should not deviate too much from other researchers in the choice of general direction. "

"Well, I agree that the performance potential of all-polymer or all-small-molecule devices is really limited," Chen Wanqing asked again: "Then there are only two options left, PDI series and A-D-A series, which one do you prefer? ?”

"Both paths have their advantages and disadvantages." Xu Qiu paused and said, "To be honest, I haven't thought about it yet."

"Actually, I am more optimistic about the A-D-A series." Chen Wanqing said.

"Oh? Why?" This time it was Xu Qiu's turn to be surprised. He had a preference for these two routes in his heart, but they were at most four or six. He was still struggling, but the senior had already directly identified one of them a route.

"A woman's intuition." Chen Wanqing said with a smile, and Han Jiaying, who was watching beside her, couldn't help but chuckle.

"Okay," Xu Qiu held his forehead, looked at the junior, then at the senior, and asked tentatively, "Then senior, do you have any specific research ideas?"

"No." Chen Wanqing shook her head.

"Okay." Xu Qiu raised his forehead again, and sure enough, the senior sister is really as usual...

"However," Chen Wanqing changed the subject: "I'm pretty much thinking about the prospect part. Let's talk about the specific experimental ideas. Anyway, there is a winter vacation transition, so there is no rush."

"Sister, it's good that you know what you're doing." Xu Qiu didn't forget the business, and brought the topic back to the summary, and began to analyze: "The two paths have their own advantages and disadvantages, so let me explain my thinking.

PDI derivatives are optimized around the initial perylene diimide molecule. The electron mobility of this type of material is relatively high, which is comparable to that of traditional fullerene materials.

Moreover, there is a perfectly matched polymer donor material PTB7-TH. The main problem to be solved is the damage of the high crystallinity of PDI to the morphology of the blend film.

The advantage is that the path is simple, just focus on the crystallization properties of the material, and other researchers have done a lot of preliminary work, and the current basic value of efficiency is relatively high, up to 8%.

At the same time, the disadvantages are also obvious. There is only one molecular structure of PDI, which is relatively simple, the light absorption range is relatively fixed, and the upper limit of the performance of the material may be relatively low. "

"Brother, slow down." Han Jiaying suddenly interjected, "I can't remember."

Xu Qiu nodded to express his understanding. This is indeed new knowledge for the junior. She is not like him and the senior. They have recently made up a lot of non-fullerene-related literature.

So, he repeated it again, slowed down, and helped the junior to record the main points, and then continued to analyze:

"A-D-A series of small molecules are a type of small molecule receptors connected by three units A, D, and A. The two A units are the same, and the D units are usually axisymmetric, so the molecules are usually axially symmetric. Symmetrical structure.

The advantage is that the molecular structure is relatively flexible, and its physical and chemical properties can be adjusted by adjusting the structure of the D unit and the A unit, such as the light absorption range, energy level structure, and even the shape of the blended film. The upper limit of the performance of the material may be relatively high.

The disadvantage is that the current efficiency is very low, only about 6%. It is not clear whether it can be higher in the future.

And I don't know the reason for the low efficiency. There are many related theories, and it is not clear which one is correct. There is a saying that it is due to the relatively low electron mobility of the material.

There are not many people involved in this series of research, and it is mainly done by several domestic groups. Teacher Wei's friend Gong Yuanjiang is one of the main forces. "

"Well, what about your inclinations, junior?" Chen Wanqing asked, Xu Qiu's overall thinking is in place, basically consistent with her thoughts, and it's not too difficult to come to these conclusions, as long as you can thoroughly understand the dozens of related documents .

"PDI derivatives and A-D-A molecules, my personal preference is six or four, but since my sister chose the A-D-A series, then I will choose PDI derivatives." Xu Qiu said, he was influenced by Mr. Wei, and he has a deep understanding of the PDI system I have paid a lot of extra attention, and I have already had preliminary experimental ideas in my mind.

"Why, you don't want to be in the same field as me." Chen Wanqing suddenly changed her tone of resentment, and said, "Han Jiaying must be with you, hey, I have to fight alone again."

"How unlucky a beauty is from ancient times~~~" Chen Wanqing said sadly and indignantly.

"Senior sister, don't do this." Xu Qiu raised his forehead again, did senior sister watch too many TV dramas recently, and put herself into it again.

However, he patiently explained: "I'm doing it out of insurance considerations. If we both study the same field, if we fail, we have to start from scratch. But if we separate into two fields, suppose one of the fields With a major breakthrough, if there is no prospect in another field, you can temporarily give up and focus on the field that made the breakthrough together.

As long as we maintain communication, it is not very difficult for us to switch research fields to this degree. "

"Okay, it sounds reasonable, I can barely convince you." Chen Wanqing returned to normal, and then teased: "Han Jiaying, which field do you want to work in more, is it a PDI derivative?"

"Yeah, yes." Han Jiaying's cheeks flushed slightly, and she responded in a low voice.

"You two," Chen Wanqing looked at the two of them back and forth, and said, "Forget it, let's not talk about this, let's continue discussing the review."

"Well," Xu Qiu said calmly without blushing, "Then let's put forward some ideas around the two directions of PDI derivatives and A-D-A series. Other areas can be downplayed, and it doesn't hurt to write less."

Speaking of business, Chen Wanqing returned to a serious state: "I will mainly supplement the A-D-A series. During this time, I have accumulated a few ideas. First, the D unit used in the binary D-A copolymer donor material can be introduced into the In the A-D-A molecule, such as IDT and IDTT, it happens to be a large conjugated fused ring structure, which also matches the A-D-A molecule."

"Would it be too difficult to synthesize?" Xu Qiu frowned, but quickly relaxed, and said to himself: "The difficulty of synthesis is not something we have to consider, as long as it is reasonable."

"That's right, after all, it's a prospect." Chen Wanqing smiled and said, "There is also a problem with the low electron mobility and poor charge transport of A-D-A molecules. I have an idea to improve the electron-absorbing ability of the terminal A unit. You can increase the dipole in the molecule, which may solve this problem to some extent."

"That's fine." Xu Qiu nodded. The two points raised by the senior sister are almost enough as the prospect of the A-D-A series.

He began to talk about his ideas: "The main idea of ​​​​optimizing PDI derivatives is to reduce their crystallization properties. A common method is to dimerize PDI.

I think it is possible to further triplex and quadruple. Of course, it also faces the problem of high difficulty in synthesis, but from the perspective of thinking, it should be no problem.

Another idea is to change the single carbon-carbon single bond between dimers to multiple carbon-carbon single bonds, which can compensate for the decrease in crystallinity caused by dimerization to a certain extent, so as to obtain crystallinity between The intermediate state between individual molecules and dimers enables smoother optimization of material properties.

Moreover, this method can also be further extended to trimers and tetramers. "

"Not bad, very thoughtful, I think we can all try to do it ourselves." Chen Wanqing praised.

"Actually, I still have an idea, but there is too little space in the summary proposal to write it down." Xu Qiu smiled and said.

"Speak human." Chen Wanqing said angrily.

"I want to keep this idea for myself, and I don't want to write it into the review." Xu Qiu said.

"Then keep it, and count your best." Chen Wan gave him a clear look, and continued: "The four or five points we just mentioned, plus some conventional ones, such as non-halogen solvents, air stability related The research is almost done, do you have anything to add?"

"Let me add one more point," Xu Qiu said: "The N2200 system is also a D-A copolymer, which is just an acceptor polymer. The A unit is NDI, and the D unit is two thiophenes. The structure of NDI is similar to that of PDI. I I feel that PDI molecules can be used instead of NDI molecules."

"That's good. I think we might be able to publish an article." Chen Wanqing's eyes lit up, and she asked, "Are you willing to write it in the review? Why don't you stay and do it yourself?"

"I came up with this randomly. If senior sister likes it, I'll keep it for you." Xu Qiu smiled.

"That's not necessary," Chen Wanqing waved her hand and said, "I will mainly do the A-D-A series in the future."

In this way, the two embarked on two different paths again.

Last time, Xu Qiu chose the P4T system, and finally got the PCE11 material, harvested an AM and several other articles.

This time, he didn't know what the future was going to be.

It is enough to do one's best, listen to the destiny, be yourself, and have no regrets.