I Have a Research Support System

Next, Tian Qing reported on her work.

Recently, based on the effective layer materials of the bottom cell and the top cell in Xu Qiu's "Science" article, she designed several organic photovoltaic stacked devices with transport layer combinations, and initially explored the relationship between the device structure of stacked devices and interface charge recombination. There is currently no progress in the relationship between them.

It is understandable that Tian Qing's progress in the experiment is slow this time.

Therefore, this experiment involves a new CELIV test method, which she also practiced while studying.

Theoretical research and explanation will mainly be carried out by the Finnish Ronald team.

Xu Qiu did almost no experiments in the past two weeks, and concentrated on coding the articles for two weeks.

The lack of experimental data before, the data of NIM's third-party inspection, has been obtained by Mo Wenlin sent to Beijing to send samples, and the light source data was measured last Thursday.

Now the data is complete and the article has been written.

Therefore, last Sunday, two articles were submitted one after another.

Among them, one is the Y2 system, which was voted for AM.

The other one is the Y3-Y5 system, which was submitted to EES.

The reason why I chose to submit to EES for this article is simply because Xu Qiu has not submitted to this journal for a long time, so I simply submitted an article.

AM, JACS, EES, and NC are the top journals in the field of materials, and they also need to be exposed to rain and dew. Of course, NC is fine, and some are too expensive.

Moreover, strictly speaking, Xu Qiu does not have the first EES article in his hand, but there is an EES article shared with his junior, but he is the second author.

Later, Xu Qiu reported some of their experimental results on behalf of Han Jiaying and Wu Shengnan.

First of all, Xuemei synthesized two donor materials, L2, L6, and S1, and prepared organic photovoltaic cells based on these three donor materials. The device performance basically repeated the results in the literature.

At the same time, Xuemei also modified L2 and L6 materials according to Xu Qiu's instructions, and developed several donor materials including L2-F, L6-Cl, etc.

Objectively speaking, it only took Han Jiaying about two weeks to produce all these new materials, and the work efficiency is indeed very high.

The reason is that on the one hand, with L2 and L6, it is much easier to develop new materials such as L2-F and L6-Cl.

Because the optimized sites are all on the BDT unit, and the fluorine-substituted or chlorine-substituted BDT unit has ready-made materials and does not need to be re-synthesized, so it is equivalent to only using another Stille coupling reaction.

On the other hand, Han Jiaying has been specializing in the synthesis of polymer donor materials for a long time, and has a very solid background in the synthesis of donor materials. In addition, she has applied a microwave reactor that can shorten the reaction time, and Xu Xinjie, a little helper from undergraduates, The work efficiency of the school girls has been greatly improved.

In the past, it may take a week to submit a polymerization reaction from submitting the reaction to getting the product. Now, if the speed is fast, it can be completed in two days at the earliest.

React for 1 hour, reaction time 8-12 hours, methanol, acetone, n-hexane Soxhlet extraction for 12 hours, chloroform Soxhlet extraction for 12 hours, vacuum drying for 3 hours, other miscellaneous things take 8-12 hours, a total of 48 hours about.

However, although the materials have been obtained, the efficiency data has not yet been completed, and there is only a preliminary result of exploration.

Among them, the combination of L6-Cl and non-Y series receptor IDIC-4F material has the highest efficiency of 13.87%, which has surpassed the original H4:IDIC-4F system.

Xuemei did not have time to combine donor materials such as L6-Cl with Y series acceptors to prepare devices.

Because it is quite troublesome to make devices in reality, it is impossible to open and hang up directly like Xu Qiu did, and explore all systems simultaneously in batches.

Therefore, when researchers imitate others, they usually first try to find a system with a similar structure, which is the so-called control variable method, which emphasizes a step-by-step process.

Otherwise, if there is no reference, it is difficult to explain whether the final efficiency has increased or decreased.

In addition, in the past two weeks, the post-doctorate sister has basically put all her energy into helping Xu Qiu synthesize a new series of materials.

After all, she "prostituted" two high-end articles from Xu Qiu's place before, and she must have to pay them back, and the price is to help with the work.

In the end, the postdoctoral sister developed a series of Y-series receptor materials including Y11-Y20, etc. There are a total of more than ten kinds, each with a yield of about 50-100 mg.

Similar to the juniors, the postdoctoral seniors have only carried out preliminary device performance exploration.

However, she was shocked when she got it.

The H4:Y18 system with the best performance has an efficiency of 16.57%!

The performance of the H4:Y20 system is second, and the efficiency is also 16.50%!

The reason why the best performance is Y18, not the Y20 obtained in Xu Qiu's simulation laboratory, may be mainly due to the lack of repetitive experiments of the postdoctoral sisters, and the relatively large data fluctuations.

At that time, Wu Shengnan saw the newly released 16.57% data, and secretly rejoiced that his previous 14% system was not greedy for the major journal of "Nature", otherwise it would probably be buried in his own hands.

Looking at the current situation, the binary single-knot system has an efficiency close to 17%. A major sub-journal of "Nature" must not have run away, and there is even a certain chance that it can hit a CNS again.

Wu Shengnan couldn't help but sigh with emotion, it hasn't been long since Xu Qiu's last article "Science" was submitted, and now there is a new system that can reach the threshold of CNS.

Why can't I think of optimizing like this?

Why do I think of optimization as "reverse optimization"?

The post-doctorate sister fell into a short period of self-doubt, but she quickly adjusted her mentality.

Because according to her understanding of Xu Qiu, she would definitely not treat her badly. There is a saying that "there is no credit, but hard work".

Xu Qiu eats meat, she drinks some soup, and mixes up a few AM articles, which is enough.

The articles I got by my ability are not shabby.

In fact, when Wei Xingsi received Xu Qiu's experimental idea before, he was also skeptical when he learned that Xu Qiu planned to synthesize more than ten kinds of Y-series receptor materials at one time. The stride is too big, and the egg is pulled."

After all, no matter how much manpower and material resources are invested in scientific research, once the direction is wrong, the final return may be close to zero.

Some people may say, how could it be 0? At least one wrong option has been ruled out.

But in fact, there may be tens of thousands of wrong options, and only a few correct options.

Even if a wrong option is excluded, it is still inconspicuous to the total amount, because the denominator is large enough.

However, although Wei Xingsi had doubts at that time, he still firmly supported Xu Qiu.

Because no matter what, Xu Qiu has historical achievements as a support, so it is worth Wei Xingsi's unconditional belief.

Now, Mr. Wei saw such a result in the group meeting. He knew that he had made a wise choice at the beginning. He couldn't close his legs when he laughed, and his legs were crossed, shaking and shaking.

Wei Xing's thoughts are more profound:

According to the current trend, only the initial attempt has reached an efficiency of 16.57%.

If it can still be higher, even if it is only a little bit higher, it can reach 17%, and there is a high probability that it will be able to win another CNS-level article.

After all, this is a binary single-knot system now, and if it is expected to reach 17%, it will be of great significance.

This shows that the efficiency of pure organic stack devices can be rushed to a higher level in the future, and even the threshold of 20% may even be crossed!

If it can really reach 20%, the field of organic photovoltaics will usher in a transformation, and its own research group will also become the brightest one in the Hall of Glory.

Because whether it is organic photovoltaics, perovskite photovoltaics, or silicon solar cells, the photoelectric conversion efficiency is limited.

According to the Schottky limit theory, the efficiency limit theoretical value is about 30%.

However, the actual efficiency value is generally not as high as the theory, and the early 20% is already very close to the extreme value.

For example, the efficiency of perovskite photovoltaic devices, which are very hot now, has reached about 23% and 24%, and it is difficult to achieve a step closer.

This is also the reason why many people turn to two-dimensional perovskite, because there is no room for improvement in the original path, and their own research group cannot stop working, so they can only create new fields and continue research. (Water article).

Researchers have been working on silicon-based solar cells for more than 40 years, but the efficiency is now stuck at 26% or 27%.

If organic photovoltaic can reach 20%, in fact, the gap with 23% and 26% is already very small.

After that, if a series of problems such as cost and stability of organic photovoltaics can be solved, organic photovoltaics may not be able to achieve commercialization, and take part of the cake from the currently dominant silicon-based solar cells.

Wei Xing thought about the conversation he had with Xu Qiu before, including the "Science" article he submitted to, as if Xu Qiu had foreseen all of this very early on.

Could it be that this kid can predict the future?

how can that be possible.

Wei Xingsi quickly put this thought out of his mind, looked at Xu Qiu, and asked with a smile, "What do you plan to do with this job?"

Xu Qiu responded: "I plan to optimize it myself, and then start writing the article at the same time."

"Well, what journal do you plan to submit to?" Wei Xingsi continued to smile, and asked. He mainly wanted to get a feel for Xu Qiu's background and see if Xu Qiu had confidence in his work.

Xu Qiu said casually: "The last one was for "Science", so this one is for "Nature."

Hearing Xu Qiu's relaxed tone, Wei Xingsi raised his eyebrows. This is basically done, so he hurriedly said: "Very good! You can write the article first according to the template of "Nature."

Afterwards, Wei Xingsi looked at the other people in the research group, and said: "Recently, the experimental resources in the group will be given priority to Xu Qiu, Wu Shengnan, Mo Wenlin, you guys should cooperate with Xu Qiu in the experiment, Wu Feifei, your perovskite experiment You can take it easy..."

"No problem." Wu Feifei nodded, feeling a little complicated in her heart, and sure enough, "one thing, if it happens for the first time, there will be a second time."

Although the spin-coating glove box is separated from the organic and perovskite ones, there is still only one evaporation glove box. If the organic team still maintains the original speed of a batch of devices a day for experiments, the perovskite team basically needs to shutdown.

However, Wu Feifei doesn't have any "dark" thoughts, after all, the overall situation is the most important thing.

Moreover, although Wu Feifei did not publish "Nature" and "Science", she is also a witness. Xu Qiu is still her junior, Wu Feifei and You Rongyan.

Xu Qiu's report brought the group meeting to a climax.

After the climax, Han Jiaying continued to report.

The various characterization data of the PTQ2 materials of the school girl have been collected, and the data is sorted out, and the article is written, and the target journal is JACS.

The main highlight of this work is the "non-halogen solvent". After two weeks of optimization, the efficiency of the device processed with tetrahydrofuran THF has exceeded 13%. In the article using non-halogen solvent, the efficiency is the highest.

Now the organic photovoltaic team led by Xu Qiu has always been a pioneer in the field of organic photovoltaics, and the systems that are taken out casually are the best systems in a certain segment, so I want to publish an article on the top journal of a district The difficulty is not great.

This is also the status quo of the scientific research circle. If you want to develop in this circle, whether you follow the right people, choose the right research direction, and whether you are lucky or not may be equally important. The importance of personal efforts and abilities can only be ranked second. Three, the fourth place.

Even Cao, who can publish seven "Nature" articles in a row, may still be able to stand out if he changes his supervisor and research direction, but it may not be as bright as it is now.

Including many successful people, the reason for their success is actually the result of a series of coincidences.

If he lost his memory, went back to the beginning, and walked the road of life again, he might accidentally make a wrong choice, and he would not be where he is now.

In many cases, success cannot be replicated.

For another example, some "outstanding youths" may have achieved outstanding results because of better luck when they were young, but when they are old, they have no good jobs.

This is not necessarily because they are paddling, it may simply be bad luck, and doing one field is inferior to another field.

In an industry like scientific research that depends on the sky, there is nothing anyone can do about such a wicked thing.

The two articles AM and JACS of Wu Shengnan's Y1, Y6, and Y7 systems have also been submitted after supplementing the NIM and light source data.

Mo Wenlin has developed a stacked device based on Y series acceptor materials, replacing the COi8DFIC material used in the previous top cell with Y4 material, and the bottom cell still uses the IDIC-M system.

In the end, the efficiency of stacked devices reached a maximum of 15.5%.

Although this value is not as good as the 17.3% reported in Xu Qiu's previous contribution to "Science", it can be regarded as a certain breakthrough.

Mo Wenlin found that the main problem in this system is the current mismatch between the top battery and the bottom battery.

If we dig deeper, it is essentially that the light absorption edge of the Y series acceptor material is around 900 nanometers, and the light absorption edge of a better top cell material should be around 1050 nanometers in theory.

It is now able to achieve 15.5%, largely due to the support of the efficiency of the Y series materials themselves, coupled with the continuous optimization of the stacked device processing technology by the current research group.

If you want to further improve the performance of the device, a more suitable improvement direction is to synthesize Y-series acceptor derivatives with ultra-narrow bandgap, such as developing an acceptor material with a bandgap of about 1.1 eV, so that the light absorption of the material falls Around 1050 nm.

However, Xu Qiu doesn't have time to deal with this matter right now.

His main work now is to replicate the results of the L6-Cl:Y20 system in the simulation laboratory.

According to the latest results in the current simulation laboratory, the efficiency of the L6-Cl: Y20 system has reached 18.55%.

In reality, if you want to achieve more than 18%, there is still a very good chance.

Several undergraduate students attended the group meeting and made some reports, either literature reports or work summaries.

Although what they said was not of much use to others, it was a rare experience for them themselves.

Xu Qiu's ability to speak and report at the beginning was actually not very good, but he has been participating in group meetings for the past two years, which has greatly improved his ability to speak and report now.

Fan Wentang is mainly working for Mo Wenlin recently, preparing stacked devices, and he is already very familiar with the entire device manufacturing process.

At the same time, Xu Qiu can sometimes see Fan Wentang revising his master's thesis, which is also preparing for his graduation.

After the group meeting, Wei Xingsi called Wu Feifei, Wu Shengnan and Xu Qiu to Jiangwan Xiancai's 513 office.

"Today, we are going to submit the online versions of the two fund projects, and then print them out for review by departments and schools." After Wei Xingsi finished speaking, he turned around and added:

"Xu Qiu, you can help with a simple pass, and then go to the experiment, don't waste your time too much, we can do it here."

"Okay." Xu Qiu nodded. In fact, most of the work for these two fund projects has been completed, and only the final delivery work is left.

The delivery process is similar to Xu Qiu's previous investment in the Sino-Swiss STINT cooperation project, because most of the domestic national funds are issued through the National Natural Science Foundation of China, so the process is similar.

That is to say, you need to fill in a lot of things such as academic achievements, representative works, everyone's resume...

After the online application is completed, you still need to print out the documents, ask the departments and schools to review and stamp them, and finally mail them to the Fund Committee, just wait patiently for the results.

Originally, Xu Qiu planned to talk to Mr. Wei about graduating early today, but judging by the current situation, they will probably be very busy.

Moreover, Wu Feifei and Wu Shengnan were present, so it was difficult to speak, so he returned to the laboratory to prepare for the experiment.

The MRS conference in the beautiful country started on April 1st, and now it is March 7th, and there are still about three weeks before the trip to the beautiful country.

Xu Qiu planned to publish this "Nature" article within three weeks.

Although it sounds unbelievable, three weeks is really short for an article of the level of "Nature", but it is actually not impossible.

On the one hand, the organic photovoltaic team is now very strong, with sufficient manpower.

There are nine people in total, Xu Qiu is the team leader, Wu Shengnan leads Yin Houlang, mainly for the synthesis of acceptor materials, Han Jiaying leads Xu Xinjie, mainly for the synthesis of donor materials, and Mo Wenlin leads Fan Wentang, mainly for device synthesis preparation.

Finally, there is Tian Qing, who makes up the numbers, and Chen Wanqing, who "is in Cao Ying and his heart is in Han", who can occasionally play a role.

On the other hand, now that Xu Qiu knew the result, it was almost not difficult to repeat the process, and there was no long trial and error process.

Moreover, Wu Shengnan and Han Jiaying have already completed the most troublesome steps of synthesizing materials.

At the same time, for the light source test, Xu Qiu also made preparations in advance. In the test last Thursday, he got the light source data of several new materials.

Therefore, Xu Qiu feels that there is still a great opportunity to produce an article in "Nature" in three weeks.

Back in the laboratory, Xu Qiu chose sub-optimal conditions, and with the assistance of Mo Wenlin, prepared a batch of devices including L6-Cl: Y18, L6-Cl: Y20, etc.

His requirements are not high, as long as the efficiency of this batch can be achieved above 17.0%.

Xu Qiu intends to increase the efficiency by 18% through three batches of devices, increasing by about 0.5% each time, so that it will not appear obtrusive and will not delay too much time.