I Have a Research Support System

Back at 216, Xu Qiu went to the glove box to prepare two solutions, based on his third-generation 8 series and Xuemei's B4T series, which are the two most efficient 3D-PDI systems. When formulated, the concentration of the solution is increased by about 4%, and he intends to use the new strategy introduced by solvent additives just developed today.

Then, he used the zinc oxide prepolymer solution left by his schoolgirl on Sunday and the cleaned ITO substrate to spin-coat 20 zinc oxide substrates, and placed them on a heating stage at 200 degrees Celsius for high-temperature annealing.

In the afternoon, Han Jiaying and Chen Wanqing took the school bus and left for Zhangjiang to do synthesis. The main job of the school girl is to synthesize her second-generation B3T/B4T materials in large quantities, and at least 200 mg of the final product must be obtained; the 1,3-indanedione (unit A) bought by the school sister is still on the way She intends to prepare the formylation reaction of the D unit first, and then directly synthesize the A unit when it arrives.

At twenty past one, Xu Qiu entered the laboratory, preparing to make a batch of devices.

Sun Wo also seemed to have the idea of ​​spin coating, but after seeing Xu Qiu, he took the initiative to avoid the glove box.

Xu Qiu nodded kindly to Sun Wo, put the annealed zinc oxide substrate into the glove box, then carefully added DIO to the two bottles of solution using a new strategy, and then gently shook the bottle for one minute to allow DIO to be evenly dispersed in the solution , and finally clean the glove box atmosphere for 5 minutes, then enter the glove box again and start spin coating.

This time, he directly adopted the best conditions he found in the simulation laboratory as his own experimental conditions.

In the process of spin coating, Xu Qiu was very serious and focused, trying to catch the flash of inspiration from the last experiment.

However, 20 devices were spin-coated, and there was no sudden inspiration.

Xu Qiu had no choice but to shrug his shoulders helplessly, and transferred these devices to the evaporation cabin to start the evaporation.

While waiting for the vacuum to drop, he was not idle. He took about 1 mg of samples of more than 20 products and intermediate products brought back by the school girl, put them into NMR tubes, added deuterated chloroform to dissolve them, and went to the aging building. A sample was sent to test the NMR hydrogen/carbon spectrum.

After rushing back from the aging building, he continued to evaporate and test non-stop.

In the end, the highest efficiency of this batch of devices reached 7.35%, and the system of Xuemei also reached 6.50%.

Seeing this result, Xu Qiu breathed a sigh of relief, it wasn't unexpected, and he didn't expect to reach the highest value of 7.50% in the simulation laboratory at one time, as long as he could get close to this value.

After all, the highest value obtained in the simulation laboratory this time is different from the previous ones. In the past, it may have been the highest value among several or more than a dozen experimental results, but this time after repeated optimization, it is the result of nearly a hundred experiments. .

It looks like 7.50%, but it is actually about 7.30±0.20%.

This time, only 10 of the 20 devices belonged to Xu Qiu himself, and the number of samples is not too much. As long as the result falls around 7.30%, it is considered normal.

...

In the next two days, Xu Qiu made two batches of devices in a row. At the same time, he also sent samples of the more than 20 products and intermediate products for elemental analysis.

These basic characterization tests involving molecular structure, all intermediate products must be carried out;

Characterization methods for effective layers or devices, such as light absorption, energy level testing, and microscopic morphology, do not need to be exhaustive, as long as the final product is considered.

After making three batches of devices for three consecutive days, Xu Qiu finally repeated the efficiencies of 7.48% and 6.60% in reality.

When he was doing the experiment, he was always thinking about whether there is any place that can be improved better, especially some optimization methods that are difficult to achieve in reality, but can be achieved by using the simulation laboratory.

He really found a way to use the simulation experiment system II to optimize the transmission layer of the battery device.

In reality, for the transport layer, the usual practice is to do a wave of exploratory experiments before the experiment starts, confirm a set of experimental conditions, and fix them for long-term use.

On the one hand, in reality, if you want to optimize the transport layer, such as changing the film thickness of evaporated molybdenum trioxide, you need to re-evaporate the device every time you change the conditions. In addition, the experimental data will fluctuate, so a large amount of data is required to confirm Optimum conditions, the time cost of the experiment is very high.

On the other hand, the transport layer has little effect on the performance of the device. After establishing a set of general conditions, it may not be able to exert 100% effect in all systems, but it can stably exert more than 95% effect in most systems. This is enough, and there is no need to re-explore every time a system is changed.

But Xu Qiu has Simulation Lab II, which can perfectly solve this problem. Dozens of evaporation machines work at the same time, and can completely explore the conditions in one wave, and it will not cost too many system points.

I didn't expect this before, the main reason is that Xu Qiu didn't do device optimization work for a long time after opening the simulation lab II, and also was affected by the mindset.

Now that his mind has been opened, Xu Qiu's thoughts diverged instantly, and he thought of many ideas:

For example, in addition to optimizing the film thickness of molybdenum trioxide, the preparation conditions of zinc oxide can also be explored, including film thickness, annealing temperature, annealing time and other preparation processes.

For another example, you can try a device with a positive structure. Although the performance of the inverted structure is better in most cases, and Xu Qiu has become accustomed to using the inverted structure device after long-term experiments, it is easier to prepare, but there are exceptions. possibility.

In addition, there are some new transmission layer materials developed by other scientific researchers, such as PFN and PDIN, which have been commercialized and are not expensive. You can buy some from the optoelectronic material company in Shencheng.

The film thickness of the metal electrode does not need to be optimized, because as long as the film thickness exceeds a certain threshold to ensure that the device does not break, the specific thickness is not important, even if it is evaporated to a thickness of 1000 nanometers, it is no different from a thickness of 100 nanometers. It is not impossible to reduce the efficiency by 0.01% if it is 10 times larger.

Of course, the type of electrode still needs to be considered. There are three commonly used electrodes, and the work functions of gold, silver, and aluminum are different.

However, with the exploration experience in the previous PCE11 period, Xu Qiu has already explored this aspect, and the best electrode in the current system is silver.

Based on these ideas, Xu Qiu gave instructions to the simulation experimenters:

Based on the existing optimal experimental conditions, optimize the processing technology of two 3D-PDI series battery devices. The first priority is to control the film thickness of molybdenum trioxide, the second priority is to control the preparation conditions of zinc oxide, and the third priority The first level is the attempt of positive structure devices, and the fourth priority is the introduction of new transport layer materials (there is no material for the time being, and it is frozen).

Generally speaking, this time it was a mistake. After three consecutive days of practice, the previous fleeting inspiration was not caught, but a new experimental inspiration was generated instead. Xu Qiu concluded by himself, Then he said with emotion:

It's just that the consumption of points is a bit fast. It's a bit stretched to get 3,000 per week. Fortunately, I had the foresight to accumulate a lot. It's still enough for the time being. I hope that the next time the authority is raised, it can make up for it.

...

Wednesday night.

Because Wei Xingsi is going abroad this Thursday, he is quite busy these days. After the group meeting on Monday, he basically didn't manage the laboratory much, and was busy with his own affairs all the time.

Now that I'm finally ready, and when I'm free, I plan to have a heart-to-heart talk with the students and learn about the latest experimental progress.

The first person to be called was Wu Feifei, but it wasn't long before she entered 218, and she came out of the office about three minutes later.

Xu Qiu, Teacher Wei is looking for you. Wu Feifei said, looking quite happy.

Okay. Xu Qiu responded with a nod. Today's experiment has been completed, and there is nothing else to do. At this time, he is reading the literature, trying to find some inspiration from it.

After hearing Teacher Wei's summoning command, Xu Qiu immediately put down the literature, got up and went to 218, but he was slightly surprised that the order is usually Duan Yun, but that's not important.

How was the experiment? Mr. Wei said lazily while sitting at the desk, leaning on the back of the swivel chair, as if a little tired.

I made three batches of devices in a row this week. Based on my third-generation 8 series and Han Jiaying's second-generation B4T series 3D-PDI, the current highest efficiency... Xu Qiu thought about it, and kept a hand as usual, respectively 7.03% and 6.38%, there is still room for further improvement. By the way, he also answered the questions that Teacher Wei might ask next.

7%! Wei Xingsi's eyes lit up, and he straightened up. Then he stared at the pen container on the desk, lost in thought, and unconsciously tapped the table with his fingers. He didn't know that Xu Qiu had hidden his hand. If we consider the usual situation, the chance of another breakthrough in device efficiency in just three days is actually not high, so he was a little surprised to get this news.

After a while, Wei Xingsi suddenly looked at Xu Qiu and said, If I remember correctly, the current world record of the PDI system is about 8%.

Yes, the current highest efficiency is 7.92%, Xu Qiu responded with a nod, and then introduced in detail:

It's the work just published last year. The trimer and tetramer of PDI, the bay position is connected through a vinyl group to form a fused ring, and the donor material is PCE10. The article was published on AM.

Xu Qiu is now going to challenge the efficiency record of PDI. Naturally, he has read the original record many times, and he remembers it very clearly. This article also gave him experimental inspiration. When designing 3D-PDI molecules, the inspiration source of fused rings is is here.

Do you have the confidence to surpass them? This was an interrogative sentence, but Wei Xingsi said it abruptly as an affirmative sentence.

I'll do my best. Xu Qiu didn't talk too much.

Okay! Wei Xingsi nodded with a smile, If the efficiency of the device can be improved, a big article can be written.

Wei Xingsi already had a solid foundation in his mind. If Duan Yun said I will try my best, don't think about it, the job will probably be cold, because Duan Yun likes to brag, and when he stops bragging, it means that there is a big problem; Qiu is more stable, and being able to say this means that he is at least 50% sure.

When different people say the same thing, they mean different things. As a tutor, Wei Xingsi thinks he is quite accurate in grasping the students' ability, personality, and behavior style.

After a pause, he continued to ask, By the way, what's the result of TRPL?

It's okay. I got a preliminary conclusion before that the fused cyclization of 3D-PDI molecules can significantly improve the ability to split excitons between receptors. Xu Qiu said.

That's right. If you add more theoretical research, you may even have a chance to impact the sub-journals of Nature, NC, or the new sub-journal of Science, Sci. Adv. Wei Xingsi said with emotion:

In the field of PDI, there have been no articles in the Nature and Science series for many years.

Xu Qiu hummed, but didn't respond much.

In fact, except that as early as 2001, PDI was first used as an acceptor material in the field of organic photovoltaics and published a main issue of Science, none of the articles published in the PDI series over the years is comparable to Nature, Science detached.

R.H.Friend, one of the authors of the Science article, is one of the pioneers in the field of organic photovoltaics.

The specific content of the article is an organic photovoltaic device based on the PDI acceptor, which has obtained a photoelectric conversion efficiency of 1.95% under the light condition of 490 nanometers.

This is just a slag-like achievement now, not to mention the low efficiency, and the lighting conditions are only monochromatic light, which is not the data under the standard solar spectrum, but it was considered a breakthrough at the time, which means that the researchers finally Alternatives to fullerene derivatives have been found.

Unfortunately, for so many years, the PDI series has not lived up to expectations. AM, EES, JACS, Angew (Germany) have published more than ten articles in the top journals of materials and chemistry, but one article is related to Nature and Science. There are no sub-journals, not even a sub-journal of Nature like NC.

This situation is like some researchers playing by themselves in a small circle, but they can't get out of the circle.

In the final analysis, non-fullerene acceptors are only a subdivision of the large research field of organic photovoltaics, and PDI is a subdivision of non-fullerene systems.

Unless it can achieve breakthroughs in subdivided fields, such as breaking through the total photoelectric conversion efficiency record (12%) in the entire field of organic photovoltaics, the meaning will naturally be different.

Break the record NB of the PDI system?

Naturally it is NB.

But there are even higher records above.

just like:

Is it worth a million dollars? so so.

Do you have a lot of wealth? It's okay.

Is it worth billions of dollars? This is great.

But there are also billionaires on it.

Therefore, now having the opportunity to seek a sub-journal of Nature or Science, Nat. Commun. (NC), or Sci. Adv. (SA), is considered a big step forward.

Of course, in academia, different researchers in different fields have deviations in the positioning of different journals, just like the dispute between AM and JACS, whether the conversion ratio is 1:1, 1:2, 2:1 or others, no one Can speak clearly.

Some people look down on NC, thinking that there are a lot of flooded articles on it, and they also charge a lot of page fees, which is not as good as AM or JACS, but if you ask them to try it on NC, they will wither in an instant.

Relatively speaking, in the field of organic photovoltaics, there must be more research groups that can irrigate AM and JACS than those that can irrigate NC.

As for the comparison between NC and SA, relatively speaking, NC is an old publication, which is relatively stable, while SA is a new publication, and there are elements of gambling in it. It is hard to say what the future will look like.

Therefore, Xu Qiu still prefers NC.

This is a lesson learned from the past, just like when the sub-journal of Nature Sci. Rep. (SR) just came out, many people thought that NC was second, and submitted many good articles to it, waiting for appreciation.

Now that SR is out of the district, it is the third SCI district. People are suddenly dumbfounded, and they are embarrassed to introduce to others the work they voted for SR back then.

However, for Xu Qiu, these are still in the imagination stage for the time being.

When the device efficiency reaches more than 8%, there will be a chance to turn these into reality.

PS: Last week, on the basis of 6,000 words updated every day, a few hundred to more than 1,000 words were added. The accumulation of small amounts made more, and 4,000 words were added in a week. 100 monthly tickets and 4 of last week’s 2,000 recommendation tickets have been combined. Qianjia is still on.

The author is very virtuous, right? Please ask for another wave of monthly tickets and recommendation tickets.