I Have a Research Support System

Chapter 174 PCE11 (Please subscribe and recommend tickets)

At around 1:30 in the afternoon, Chen Wanqing and the others returned to Caiyi 216 one after another.

Xu Qiu felt that it was necessary to tell them what happened at noon, especially the senior sister and Wu Feifei, who were also the main members of the glue dispenser, so he said:

The heated glue dispenser delivered by Mr. Gong arrived at Caiyi this morning. I just took it back from the concierge and put it directly in the spin coating glove box.

Is it ready? Wu Feifei asked.

It's ready.

Is the glove box not leaking air?

Although I encountered some minor troubles, they have been resolved. I finally checked the airtightness of the glove box and there is no air leakage.

What about the original glue dispenser?

Oh, I put it in a box and put it in the corner of the laboratory. Xu Qiu explained patiently.

That's good. Wu Feifei finally nodded in satisfaction.

It's not very strange for Xu Qiu to turn Wu Feifei into a problem baby. After all, she is the person in charge of the spin-coated glove box. If something goes wrong, she will not escape Teacher Wei's sanctions.

Is the heating function of the new instrument easy to use? Chen Wanqing continued. She plans to study the effective layer thin film of P4T system under different treatment temperatures recently. This instrument is quite important to her.

I don't know, I was only responsible for the installation, Xu Qiu pointed to the direction of the laboratory, and continued: I handed over the heating function to Han Jiaying to try.

Okay, I'll go and have a look.

Shortly after the senior sister left, Wu Feifei suddenly asked: Can you say that the organic thermal spin coating method can be replicated in the perovskite system?

Xu Qiu said without hesitation: I think we can at least give it a try. Anyway, now that the equipment has arrived, it's definitely a good idea to give it a try.

Immediately, he thought for a moment and asked, Have you seen related articles and reports on thermal spin coating?

Wu Feifei shook her head and said: I haven't seen such work at this stage. Everyone is mainly working on new perovskite materials. By adjusting the molecular structure, there are occasionally additives and post-processing work.

Xu Qiu touched his chin and analyzed: I guess it's because perovskite photovoltaics is a field that has just emerged in the past two years, and there are too many directions for research. Maybe it's almost time to study the general direction, such as the current field of organic photovoltaics. However, researchers will find another way to find some subdivided research directions, and of course it is not ruled out that some people have tried thermal spin coating and found that thermal coating is not a good method for the existing perovskite system.”

I didn't expect your thinking to be very clear. Wu Feifei's eyes lit up, and said with a smile: It seems that we can discuss more when we have time, and get some suggestions from you.

I can only give some immature suggestions. Xu Qiu hurriedly waved his hands and said modestly:

You have published a top journal like EES, you still need to come to me to discuss.

My EES was a review article, and it was mostly luck that I was able to publish it. The main reason was that the bosses were busy rushing for efficiency. There were not many people who wrote the review, so I missed it. Wu Feifei said:

The gold content of the review is far inferior to the specific experimental work. By the way, didn't you submit an AM before, how is the situation now?

It's been almost two months since the submission, but I haven't received any news yet, Xu Qiu said a little depressed:

Teacher Wei checked the backstage of the account last week and said that the article was being submitted for review. He also sent an email to the editor to remind him, but he doesn't know what the situation is now.

It is estimated that there are reviewers whose review speed is relatively slow, Wu Feifei comforted:

Good things take a long time, maybe you will receive the news tomorrow, and the article will accept it directly.

I would like to borrow your good words.

...

After resting for a while, Xu Qiu went to the laboratory.

He originally arranged four experiments for Han Jiaying this week, but so far she has only completed two.

And now she has a new task. On the one hand, she has to explore the optimal experimental conditions based on the heated glue homogenizer, and on the other hand, she has to prepare samples of the light source for Saturday.

Obviously, she didn't have time to help him with the experiment anymore.

No choice but to play in person.

When passing by the glove box, Xu Qiu saw the junior sister operating inside the glove box, and the senior sister was watching from the side.

He walked over, stood between the two, and asked casually, How does the new instrument work?

This instrument is really powerful, Han Jiaying said happily:

I've tried coating a dozen pieces of glass, and the success rate so far...how many do you think?

Looking at her appearance, there is no need to be conservative, she must have not failed, Xu Qiu said calmly:

100%.

Bingo, brother understands me. Han Jiaying said happily, It all worked out.

Yes, yes, what about the temperature control of the instrument? Xu Qiu asked.

The temperature control is very stable, and the temperature deviation during the spin coating process is within... Han Jiaying thought for a while and said, Within plus or minus 3 degrees Celsius.

Not only that, the quality of the obtained film is good, and the center of the coated film will not appear as a big circle like before. Chen Wanqing also added with a smile.

That's good. Xu Qiu nodded, these are all expected results.

After understanding the basic situation, he didn't leave in a hurry, and stayed for a while to watch the experimental operation of the school girl.

On one side of the heating and stirring table, the heating temperature of the solution is 100 degrees Celsius, and the setting temperature of the other side of the spin coating instrument is also 100 degrees Celsius, the rotation speed is set at 3000 r.p.m., and the rotation time is 35 seconds.

Start experimenting.

Jiaying Han first picked up a clean piece of glass, and after blowing the surface with a nitrogen gun for about 1 second, placed it in the center of the suction table;

Then unscrew the cap of the solution bottle on the heating stirring table;

Then press the start button of the homogenizer, and after the platform starts to rotate for about 3 seconds, quickly draw 20 microliters of solution with a pipette gun, and spray the solution onto the high-speed rotating substrate;

Squeeze the pipette tip into a dedicated trash can when finished;

Finally, tighten the cap of the solution bottle.

The whole process is smooth and flowing.

As expected of the apprentice I brought out. Xu Qiu blurted out.

As soon as he finished speaking, he felt a little embarrassed, why he accidentally expressed his inner thoughts.

Chen Wanqing didn't speak, but just stared at him with a half-smile.

Han Jiaying rolled his eyes at him, and said cooperatively, Yes, yes, it's all taught by senior brother.

It's just that this distasteful tone...

It seems that it is not suitable to stay here for a long time.

After Xu Qiu ordered a few words, he resolutely slipped away and ran to the evaporation glove box next door.

He also has a lot of experiments to do today, and he needs to supplement and test the CELIV and TOF data of the four systems.

...

After such a small episode, Han Jiaying stopped the spin-coating experiment based on glass slides.

She has basically figured out this new instrument.

At present, it can reduce the operation difficulty of the true hot spin coating method a lot, almost down to the ordinary spraying method.

Of course, whether the new method can replace the original operation method and the specific effect still needs to be verified by the device test results, which is also the task Xu Qiu entrusted to her.

Han Jiaying looked at the senior sister next to her, and said proactively: I'm going to use new instruments to make a batch of devices later, do you have a system for the senior sister?

Hmm... Chen Wanqing thought for a while, and said, Let's make a few tablets. The solution is in my lock box, marked as P37P, P55P, and P73P. The date should be around December 5th, and there should be some leftovers. Some.

The solution of the three systems of P37P is based on the blend solution of her ternary conjugated copolymer system and PC[70]BM, P37 represents the molar ratio of the two A units in the donor material, and P represents PC[70] BM.

This is a simplified version of the callout form.

Because the optimal conditions have been explored, the conditions such as solvent, concentration, and D/A ratio are fixed and can be omitted, and only need to mark the material and date.

After all, the small brown bottle containing the solution is brown all over, and it is difficult to distinguish the words written on it with a marker pen, and the diameter of the bottle cap that can be written is only about 1 cm, and there is not much space.

Instead of writing a bunch of densely packed small characters, it is better to be more generous and mark out the main content.

The senior sister's lock box was placed on the innermost shelf of the glove box. Han Jiaying tried her best to reach that direction, but she still couldn't reach it.

No way, her hands are short, and the glove box is more than one meter deep.

Fortunately, this is not the first time she has encountered this situation. She picked up a pair of tweezers about 30 cm long, clamped one end of the lock box, and took it off.

In order to ensure that the solution bottle does not tip over, the whole process is very smooth.

Then, she opened the four locks next to the lock box, found three bottles of the target solution from the solution box of the senior sister, checked it, and found that there were more than 200 microliters of the solution, and there was no obvious solid substance left on the inner wall.

In organic solutions prepared in the laboratory, if the initial solution volume is 1 ml, then 200 microliters is an important threshold.

When the remaining solution volume falls below the value of 200 μl, the solution is usually discarded, unless it is used for some less important experimental characterization.

Because the concentration of the solution at this time has a very large deviation compared with the initial preparation, the deviation usually exceeds 20%.

Han Jiaying transferred the three bottles of solution to the sample iron tray on the heating and stirring table, and then asked: Do you only need to make these three systems?

Yeah, Chen Wanqing nodded, and added: Actually, it's mainly experimental. My system has been spin-coated before, but it didn't work.

What about the spin-coating conditions? Han Jiaying asked, while fastening the lock box, picked it up again with long tweezers, and put it back to its original place.

The conditions should be the same as before. I'll look for it... After finishing speaking, Chen Wanqing's eyes wandered among the row of sticky notes on the edge of the glove box.

These sticky notes are pasted on positions that do not affect the normal use of the glove box, and are usually written with experimental conditions, experimental procedures, experimental memos, etc.

The sticky notes are quite convenient to use, just tear them off when you don't need them.

However, in the early days of the establishment of the laboratory, Tian Qing directly used a black marker to write and scratch on the glass of the glove box for the convenience of the experiment.

Later, she was jointly stopped by Chen Wanqing and Wu Feifei, two glove box managers. Tian Qing also deeply realized her mistake and wiped off the handwriting with acetone.

Later, they all used sticky notes to record information.

A few seconds later, Chen Wanqing pointed to a sticky note and said:

That's it, the condition is that the speed is 2500... By the way, how many pieces do you plan to make in total? Chen Wanqing said.

I've prepared 24 zinc oxide substrates this morning, let's use them up today, Han Jiaying said.

How about giving me six slices? Chen Wanqing tentatively asked:

Three slices were compared with the previous optimal conditions, and three slices were hot-coated at 100 degrees Celsius.

No problem. Han Jiaying glanced at the content of the note again, remembering the location of the note.

Then you make the device first, and I'll come back after you're done, thank you for your hard work. Chen Wanqing said, she also had an experiment today, but she still gave up the glove box to Han Jiaying, after all, the process of making devices is long, Priority is higher.

Okay. Han Jiaying nodded.

After Chen Wanqing left, she suddenly said, Brother, what system do you want?

Just as Xu Qiu put a device in the sample holder, he was about to test CELIV, but he only listened to the beginning of the conversation between the senior sister and the younger sister, and then focused on the experiment.

After hearing the key word senior brother, he froze for a moment, then quickly realized, and replied, Let me think about it first.

His system has been proved to be effective by thermal spin coating, so the initial strategy should be to directly select the optimal material and fine-tune it.

If the performance of the device can be further improved, it will not be too late to push it to other systems, and the final result can be updated in the article he submitted to AM.

Xu Qiu quickly made up his mind and said:

I only need to make one system, P2FBT4T-2OD and PC[70]BM. You should know where the solution is. If you have the conditions, you can watch it.

Let me see, Han Jiaying murmured softly, Senior brother believes in me so much...

What did you say?

It's nothing, brother, feel free to experiment, and leave it to me.

...

Throughout the afternoon, Xu Qiu was busy with his own experiments, and only occasionally chatted with Han Jiaying for a few words, but none of them were related to the specific details of the experiment.

The general direction has been pointed out, and the specific details are left to her to supplement. It should not be a big problem. After all, the scientific research level of the junior is reassuring. He feels that his identity is more and more like a mentor.

At around eight o'clock in the evening, Han Jiaying's device evaporation was completed.

Although Xu Qiu didn't care much about her specific experiment process, he was still very concerned about the results of the experiment, so he moved to her side.

In the laboratory, besides Xu Qiu and the others who were preparing for the test, Chen Wanqing was also doing the experiment.

However, she was studying new instruments in the spin-coating glove box on the other side, and she didn't have much hope for the thermal spin-coating devices of the three systems that she made in the afternoon.

Her attention is completely focused on the new research work, which is based on the subdivision work of Xu Qiu's P4T material, and investigates the influence of different processing temperatures on the crystallization properties.

The research group is generally full of people at night, because postgraduate courses are rarely arranged in the evening, and most of the activities in the school are during the day.

In the office outside, Tian Qing was working hard to type and write the article, because she was too procrastinating, Teacher Wei gave her an ultimatum yesterday, this week her article must be finished, corrected, and rejected.

Wu Feifei is reading more than a dozen perovskite-related documents that have just been released. She originally planned to do experiments and try new instruments, but the glove box was occupied by the organic trio all day today, so she did not fight them.

Duan Yun is dealing with thermoelectric data. He has been smiling all these days. The experimental work seems to be going well, and it looks like an article will be published soon.

Although it took nearly half a year to build his equipment, his scientific research seems to have entered the fast lane after the equipment was set up.

There is some truth to the saying that sharpening a knife does not cut firewood by mistake.

Han Jiaying used tweezers to remove the substrate from the sample holder, and put it neatly into two petri dishes.

There are a total of 24 substrates, and most of the effective layer films are completely coated, only one or two seem to be slightly flawed.

The electrodes on the device are bright and shiny.

Commonly used metal electrodes are gold, silver, and aluminum.

The aluminum electrode generally used by default in Teacher Wei's laboratory is because it is cheap on the one hand, and because its performance is not bad on the other hand.

This time the electrode is shiny silver, so it is definitely not gold, and the appearance of silver and aluminum electrodes is relatively similar, but it is not easy to distinguish.

Xu Qiu judged through intuition that the probability of the silver electrode is higher, so he asked: This time, is the silver electrode steamed?

That's right, I followed the conditions of my brother when he made the highest efficiency device. Han Jiaying nodded and said, By the way, which one should we test first?

I don't even know what conditions you have fulfilled... Xu Qiu said helplessly.

Then I'll pick a piece at random, Han Jiaying said.

After speaking, she held tweezers and dangled above the petri dish, seemingly looking for a suitable target.

A few seconds later, she picked out a substrate, raised a corner from the side, then clamped it, and said, Just this one.

Okay. Xu Qiu had no objection.

He glanced at the side on the back of the substrate, which was marked XQ, 110, 2.5K.

If you guess correctly, it should refer to thermal spin coating at 110 degrees Celsius, 2500 rpm, which seems to be the optimal condition for his system.

In the past month or so, all the junior girls have been helping him with the experiments. It has been a long time since he made the device himself, and he can't remember the specific experimental conditions.

After connecting the substrate and testing equipment, Han Jiaying clicked the Test button on the computer software.

With a sound of beep, the value on the digital display screen of the source meter starts to flash.

This is the first device of this batch, Xu Qiu is still very concerned about its performance, he is staring at the indication on the source meter.

Although the bright-state J-V curve of the device and the specific photoelectric parameters cannot be displayed on the computer until the test is completed, the short-circuit current density of the device can be roughly estimated through the real-time readings of the source meter.

He noticed that when the voltage value was 0, the current value was 1.65... mA, because the numbers changed continuously, so he only memorized the first three digits.

Xu Qiu did some calculations, and the effective area of ​​the battery is 0.09 square centimeters, so the short-circuit current density is roughly 18-19 mA per square centimeter.

This value is not too low in the field of organic photovoltaics. If the open circuit voltage is around 0.9 volts and the fill factor is around 0.60, then the photoelectric conversion efficiency of the device will be close to 10%.

After a few more seconds, the test ends.

The computer automatically draws the J-V curve and displays various photoelectric performance parameters.

Han Jiaying kept staring at the computer screen. After seeing the data on it, she said excitedly:

It's more than 10%, and the efficiency is 10.12%.

That's right, a good start. Xu Qiu said with a smile.

He was not as excited as the junior. On the one hand, he deduced the result in advance. On the other hand, although the efficiency was high, it did not break through his previous record.

The junior girl's voice also alarmed Chen Wanqing, she turned her head to look, and said to Xu Qiu: Over 10%? It's your system.

It's mine, and now it shows that the film produced by the new equipment is no worse than the previous one, and at least 10% of the results have been repeated. Xu Qiu said.

That's right, keep going. The senior sister encouraged her, then turned around and continued her experiment.

Let's continue too. Xu Qiu patted Han Jiaying's shoulder.

Hmm~

Soon, she measured all six data points on the first device, with the highest efficiency of 10.18% and the lowest of 10.05%.

Brother, the fluctuation of the data seems to be much smaller than before. Han Jiaying said.

I've also noticed this situation, but I just don't know if it's a special case. Xu Qiu said: Test another piece at the same speed at 100 degrees Celsius. This condition must be done.

Yes. Han Jiaying put the tested substrate back down, put it back into the original petri dish, and then took the substrate marked XQ, 100, 2.5K.

After a few minutes, the test is complete.

This time the highest value was 10.46%, and the lowest value was 10.28%.

It seems that the data fluctuation has indeed become smaller, and the absolute value of efficiency is almost the same as my previous highest efficiency value. Xu Qiu said:

This time, it was measured at 90 degrees Celsius at the same speed.

Okay. The school girl quickly replaced the substrate and tested.

The highest value is 10.38%, and the lowest value is 10.11%.

Han Jiaying thought for a moment and asked:

The efficiency has decreased. Do you want to switch back to the 100-degree Celsius system and measure the speed at 3000?

Can.

Increased, 10.68%!

Are there any higher speeds?

There are still 3500 rpm. Han Jiaying directly found the corresponding substrate this time and started testing.

Xu Qiu calculated in his mind that so far, his system has three temperature conditions and three speed conditions.

He glanced at the substrates in the petri dish again, most of them were marked with XQ, and asked curiously, How many samples of my system did you make?

Brother has 16 pieces, senior sister Chen Wanqing has 6 pieces, and I have 2 pieces. After Han Jiaying finished speaking, she quickly added:

Don't think too much, I just want to use your system as a reference, find the law, and then transfer it to my system. After all, your efficiency is high.

Okay, let's trust you. Xu Qiu said.

That should be four conditions respectively, the speed is from 2000 to 3500r.p.m., and the temperature is from 90 to 120 degrees Celsius.

Not long after, Han Jiaying finished the test.

This piece has a maximum of 10.92%. She was overjoyed at first, and then sighed softly: It's a pity that there are no higher speeds.

Next time I have the opportunity to make another batch, Xu Qiu encouraged: It is still very possible to break through 11%.

According to the existing results, under the condition of 100 degrees Celsius, the efficiency increases with the increase of the rotational speed, and there is no inflection point yet.

Then continue to increase the speed to more than 3500r.p.m., there is hope to obtain higher efficiency.

From 10.92% to 11%, the difference is only 0.08%, so it should not be a big problem.

...

After seeing the hope that the efficiency would break through 11%, Xu Qiu's mind became active.

The current PTB7-TH donor material used as a benchmark in the field of organic photovoltaics, its alias is PCE10.

Because it is the first reported system with an efficiency exceeding 10%.

After five or six years of development, a large number of researchers in the world have continuously optimized the device preparation method, transport layer material and electrode material selection of the PTB7-TH system, published hundreds of related papers, and increased its maximum efficiency to 12%.

But so far, except for the PTB7-TH system, other organic photovoltaic materials with an efficiency exceeding 10% have not been reported with an efficiency exceeding 11%.

So, if Xu Qiu's P2FBT4T-2OD material can achieve an efficiency of 11% when it is first published, he is qualified to name this material PCE11.

Now, we are only one step away from this goal.

Thank you Lanzang Wenyuan for rewarding 2100 starting coins, liliko for rewarding 500 starting coins, I am so fat, the corner and the stars, book friends 20171231183413885 for rewarding 100 starting coins. The first order of this book is 520, which is expected... Add a new rule, weekly recommendation tickets 2000+, plus 2K, for every 1000 more, an extra 1K will be added. The list of recommended votes was refreshed on Monday today, so it was posted directly at zero o'clock, and it will be split into two chapters for distribution starting tomorrow, and the normal update time will be restored at 7:00 and 16:00.