I Have a Research Support System

After the invigilation is over, Xu Qiu's academic affairs for this semester are all settled, and then he can devote all his energy to scientific research.

Xu Qiu went straight back to Material 1 216, and found that there were not many people in the office.

A few undergraduates didn't come, most likely because they haven't finished their exams yet.

Today is the Wednesday of the 19th week, and the Department of General Materials will arrange the examination time for major courses such as degree professional courses to a very later date.

For example, when Xu Qiu took the "Nanomaterials Science" exam, the exam time was scheduled for Friday of the 20th week, which was also the latest exam time for the school theoretically.

However, for some majors, all the exams are over in 19 weeks, which is equivalent to one week more vacation for them than the materials department.

Duan Yun and Chen Wanqing were not in the office either, they probably went to their respective companies for internships.

Wu Shengnan may be doing synthesis in Jiangwan. Recently, she is synthesizing Y series materials in large quantities.

Tian Qing didn't know if she went for the exam, or why she went, anyway, she didn't see her.

Han Jiaying is in the code word liver article.

Mo Wenlin is doing experiments in the inner laboratory and continues to prepare stacked devices.

Wu Feifei and Sun Wo, who recently raised the efficiency of tin-based two-dimensional perovskite devices to 2%, are discussing the next optimization plan.

The new prospective doctoral student, Fan Wentang, sat in Wu Shengnan's seat, reading the literature.

After scanning around, Xu Qiu first went to Fan Wentang's side to find out about Fan Wentang's situation.

Now the senior sister is away from the laboratory for three days, and Xu Qiu and Han Jiaying often help in handing over the work.

For newcomers like Fan Wentang, the most important thing at this stage is to be familiar with the main experimental operation methods and to read literature in the field.

For the experimental operation, Chen Wanqing had already taken Fan Wentang through the device preparation process, but since Mo Wenlin was helping Xu Qiu to make the laminated device recently, it was not his turn to be a newcomer.

Therefore, Fan Wentang is mainly responsible for the simple work of cleaning the substrates. The first task when he comes here every day is to wash 24 clean substrates first.

In terms of literature reading, because there are enough articles published in the group, Fan Wentang only needs to thoroughly understand the literature related to organic photovoltaics in the group, which is enough for him to have a deeper understanding of the current development status of the field.

After all, the work in the group has almost reached the forefront in various subdivisions, and there are two reviews written by Xu Qiu, and we can also learn some history of the field of organic photovoltaics.

For a newcomer, it is almost enough to achieve this level in the literature in the early stage, and the rest can be supplemented by reading the latest literature while doing experiments.

Xu Qiu is quite satisfied with Fan Wentang's recent performance. The other party's understanding of scientific research is not low, and most of the time he can understand everything.

According to the current trend, Xu Qiu reckoned that Fan Wentang could be used as a complete combat force by the time the next semester started.

It's normal, Fan Wentang is a prospective doctoral student after all, which means he has more than two or three years of work experience.

Moreover, Fan Wentang was able to publish two SCI first works during his master's period, one of which was an AFM in the first district.

With these academic achievements, Fan Wentang's scientific research ability should have surpassed more than 90% of other master's students.

Of course, the reason why so many people are able to surpass so many people is mainly related to the current expansion of graduate student enrollment, which has led to more and more moisture in the word "research" among graduate students. Study for research.

Xu Qiu communicated with Fan Wentang for a while, answered a few questions raised by the other party, and then walked over to Han Jiaying to check the progress of the junior girl writing the article.

Han Jiaying was writing the description part of the photoelectric properties of PTQ series materials. When she saw Xu Qiu approaching, she was a little happy and took the initiative to chat.

Then, Xu Qiu found that the work efficiency of the school girl plummeted. While chatting and typing, several words were spelled wrong.

So, Xu Qiu said hello to the school girl, decided to sneak out, and decided not to disturb her anymore.

Xu Qiu went to the inner laboratory again to check the progress of Mo Wenlin's experiment.

Mo Wenlin is still exploring based on the ideas at the Xu Qiu group meeting, and has prepared two batches of devices so far.

Although the highest efficiency of the device she prepared has reached 16.42%, which has already exceeded the efficiency record set by the junior girl, but there is still a gap of one percentage point from the 17.36% that Xu Qiu found out.

After all, it is reality.

Compared with the simulated laboratory, in addition to the biggest difference in the longer exploration time, there are also differences in the specific sequence of experiments.

For example, the corresponding relationship between film thickness and speed, do experiments in reality, do this first if you don’t come up.

Instead, it will first explore the best conditions by adjusting the concentration and rotation speed of the solution.

Then supplement the scanning electron microscope and optical absorption spectrum characterization, and convert the corresponding relationship between film thickness, rotational speed and concentration.

Furthermore, the film thickness of the effective layer under optimal conditions is obtained, and a two-dimensional map of the device efficiency changing with the film thickness of the bottom cell and the top cell is drawn.

That is to say, in reality, the design of laminated devices is not based on the film thickness of the top cell and the bottom cell, but according to the concentration of the solution and the rotation speed.

I didn't know the specific film thickness when making the device, I only had a rough estimate, and it was more experience-based.

The main thing is to do experiments in reality, which needs to be considered from the perspective of saving time, but in the simulation laboratory, there is no need for such considerations, so how convenient it is.

Of course, this is not a very critical issue. Although the expressions are different, the logic behind them is the same.

Xu Qiu checked Mo Wenlin's experiment plan and found that she had some problems in the optimization range of film thickness.

She referred too much to the experience of the original ternary bottom battery and binary top battery stacked devices.

In fact, now that it has developed into a binary bottom cell and a ternary top cell stack device, the situation is very different.

For example, the optimal condition for the original ternary bottom battery and binary top battery is that the thickness of the top battery is 110 nanometers, and the thickness of the bottom battery is 220 nanometers.

The optimal condition for the current binary bottom battery and ternary top battery is that the thickness of the top battery is 130 nanometers, and the thickness of the bottom battery is 190 nanometers.

A film thickness deviation of 20-30 nanometers may result in a difference of 1%-2% in terms of device efficiency.

In addition, in reality, concentration and rotational speed are used as experimental conditions. When the system changes, for example, a binary system is changed to a ternary system, the film thickness obtained under the same concentration and rotational speed will also be different from before.

In other words, it seems that the position of PCBM is just moved, but in fact the difference between the two systems is already very large, so it is necessary to re-explore the conditions.

The current Mo Wenlin is equivalent to constantly groping on the edge of the 16% iso-efficiency line, and naturally it is difficult to break through.

What Xu Qiu has to do is to guide her to the center of the 16% iso-efficiency line, to find the opportunity to break through 17%.

So, Xu Qiu thought for a moment and said: "I combined the EQE curve obtained before and analyzed it with a semi-empirical model. The final conclusion is that you can make the top battery thicker and the bottom battery thinner." Thinner. Of course, don’t change the thickness too much.”

"Oh, okay," Mo Wenlin nodded, "Then I'll try it tomorrow, and now the batch of devices has been spin-coated, and the evaporation is short."

After finishing speaking, Mo Wenlin murmured in her heart: "The semi-empirical model is so NB now, can it really guide specific experiments? I always thought it was telling a story... But since Xu Qiu said it, You shouldn't be fooling me."

In fact, Xu Qiu was fooling her, but not completely fooling her, after all, he had to give his conclusion a more reasonable explanation.

This is equivalent to a known conclusion. To reverse the process, the theoretical short-circuit current density can indeed be calculated through the external quantum efficiency EQE curve and light absorption.

However, this method is rarely used in reality, because when the amount of data is not sufficient, the EQE curve of the device will deviate each time, so using the previous data to estimate the subsequent data, the results are often inaccurate.

Only people like Xu Qiu who have a lot of experimental data in their hands can make predictions.

Afterwards, Xu Qiu made another WeChat call to Wu Shengnan to care about the progress of the postdoctoral sister's experiment.

Then, Xu Qiu learned that Wu Shengnan is still in the process of synthesis, but the final product will be available soon. The synthesis cycle of Y series materials is not short, usually about ten days.

After walking around, Xu Qiu paid attention to a group of team members, and finally returned to his desk.

These are the tasks that Xu Qiu usually has to do. Now that he has become the leader of the organic photovoltaic team in the group, he needs to know the work progress of other members from time to time, and provide them with guidance at any time to prevent them from going in the wrong direction.

In fact, this is also the responsibility that the supervisors of normal research groups should fulfill.

In the next two days, Xu Qiu continued to improve the "Science" article.

Although this work is only 2,500 words long, every time Xu Qiu reads it, he can see some things that need to be revised.

Moreover, the system has been replaced one after another recently, and these changes need to be reflected in the article.

Otherwise, it will be embarrassing if there is a situation like "the efficiency of the report is for system A, but other characterizations in the article are written for system B".

In fact, many of the articles submitted by the group before, even if they are of the AM level, because the submission is relatively fast and urgent, there are actually more or less loopholes.

At least, if you look carefully, you can always find one or two language mistakes.

Of course, ordinary researchers don't care about this kind of small problem, as long as there are not many loopholes like holes in the sieve, which will affect everyone's reading.

Because, as everyone knows, when reading this kind of academic literature, including some books, what is important is the viewpoints and ideas inside the text.

In other words, what they value is the bright spots and advantages of the article. As for some minor shortcomings of the article, they can selectively ignore them. The key point is whether they can get anything from it.

Including when Xu Qiu read some articles published in the top journals of CNS, there will always be mistakes in the pictures.

However, others are others, and you are yourself. For his first "Science", Xu Qiu still has to try his best to polish it to perfection.

In addition to the article, Xu Qiu also took Mo Wenlin to make a new batch of devices, and once again made a breakthrough in the efficiency of the stacked device, reaching 16.52%.

However, the device performance in reality still lags behind the simulation laboratory a lot.

Now the simulation laboratory has repeated Xu Qiu's previous result of 17.36%, prepared thousands of devices, and fluctuated the efficiency up a bit, reaching 17.50%.

At the same time, the simulation experimenters have also learned Xu Qiu's routine, and will spontaneously reproduce devices in batches for repeated experiments, which further improves the exploration efficiency of the simulation laboratory.

In the past, a certain condition could be found to be optimal in a week, but now it may be completed in three or four days.

However, Xu Qiu had a hunch that 17.50% should also be the end of this system.

There is basically no room for further optimization in processing technology.

Unless the material of the effective layer is replaced, but that is another job.

Of course, 17% is good enough.

At the earliest time, Xu Qiu set the target at 15%, then changed it to 16%, and now it is 17%.

If you continue to sprint to 18%, what if you can't make it up.

Don't be too greedy, the current results already have a great chance to be published in "Science", and it is better to let the results be settled as soon as possible.

On Friday afternoon, Xu Qiu and Mo Wenlin prepared devices in the inner laboratory.

They plan to finish the device tonight, put it in the evaporation cabin for a day, and wait until Saturday to test the results.

At this time, Wei Xingsi walked in from the outside and scanned around. Like a guided missile, after locking on to Xu Qiu's position, he walked towards him quickly: "Xu Qiu, how is the device doing?"

"It's up to 16.5% now," Xu Qiu responded, "I plan to make another batch today, put it in a vacuum for half a day, and wait until Saturday to come and test it."

"You've worked hard, you've worked hard." After Wei Xingsi finished speaking, he glanced at Wu Feifei in the office outside, and said, "Xu Qiu, come with me."

"Okay." Xu Qiu followed Wei Xingsi with some doubts and walked to the outside office.

Wei Xingsi clapped his hands, signaled everyone in the office to listen to him, and then said:

"This is the case. Sun Wo mentioned at the group meeting that the mixed preparation of organic and perovskite devices will affect the performance of perovskite devices. I think it makes sense."

"But if you think about it the other way around, DMF and other solvents used in the preparation of perovskite devices will most likely affect organic devices. After all, they are anti-solvents."

"Since this is the case, because Xu Qiu and the others are striving to increase the efficiency of organic stacked devices, Wu Feifei and your perovskite team's experiments will stop for a while, and wait for Xu Qiu and the others to increase the efficiency. Besides, what do you think?"

"No problem." Wu Feifei immediately expressed her opinion, and Sun Wo also nodded in agreement.

"Okay," Wei Xingsi said with satisfaction: "Then the perovskite experiment will be stopped for a while. During this time, Wu Feifei, you can take Sun Wo to write the review together, and give the glove box to the organic photovoltaic team..."

Wei Xingsi turned his head and looked at Xu Qiu: "Try to make a batch of devices every day, and increase the efficiency to 17% as soon as possible, how about it?"

"Hmm... yes." Xu Qiu nodded.

In fact, the idea of ​​letting the organic team monopolize the glove box was not something that Xu Qiu hadn't considered before.

But as a student, it was not good for him to bring it up. Now that Wei Xingsi proposed it on his own initiative, and Wu Feifei and Sun Wo had no objections, Xu Qiu followed suit and agreed.

As for a batch of devices per day, it can also be done.

For example, the first batch of devices is prepared on the first night, and they are "vacuum placed" in the evaporation chamber until the next day, and then the second batch of devices is prepared during the day of the second day, and the performance of the first batch of devices is tested at the same time. Then put the second batch of devices "vacuum placed" until the daytime of the third day, and so on...

The only problem is that it needs to rotate continuously, and the work intensity is a bit high.

However, this is not a big problem. Xu Qiu decided to let himself, Mo Wenlin, and Han Jiaying take turns to carry out the experiment.

Three batches in three days, divided up, that is, each person makes a batch of devices in three days, and the work intensity is average.

In addition, since it is necessary to sprint efficiency, the regeneration of the glove box can also be done, and try to do the best in all aspects.

Recently, the oxygen content of the spin-coating glove box is often above 10ppm, indicating that the solvent atmosphere inside is very strong and needs to be cleaned up.

This may also be a major reason why Mo Wenlin's device performance cannot be improved.

So, Xu Qiu suggested: "Let's have a second life on Saturday."

Wei Xingsi had no objection: "Sure, you can arrange it."

So, Xu Qiu logged on to the school's hazardous chemicals ordering website and went to the drug warehouse to order a bottle of nitrogen-hydrogen mixed gas with a volume fraction of 95%+5%.

Because steel cylinders are pressure vessels, they are dangerous, so they should be placed in special steel cylinder cabinets in theory when they are stored in the laboratory, so as to prevent the cylinders from toppling due to unexpected situations such as earthquakes and slow down the explosion of the cylinders. Here comes the shock wave.

However, the laboratory of Handancai-216 was built a few years ago. At that time, the safety requirements for pressure vessels such as steel cylinder cabinets were not so high, and they were all fixed with temporary straps.

Now newly built laboratories basically require the use of steel cylinder cabinets.

For example, when designing the Jiangwan Laboratory, steel cylinder cabinets had to be prepared, and they were forced to adopt centralized gas supply methods, all of which were considered from the perspective of safety.

Speaking of the safety of the pressure vessel, an undergraduate student in the Department of Chemistry of Shanghai Comprehensive University had his hand broken because of improper operation of the reactor.

Recently, there have been news reports that the Institute of Chemistry, Chinese Academy of Sciences also had an accident.

It is said that there was a joint-trained master, a first-year master, a female, when the hydrogenation reaction in the autoclave was carried out, an explosion occurred during the cooling process, the skull was broken, and she died on the spot...

R.I.P.

Although Xu Qiu had never used a high-pressure reactor, he knew something about it and knew that it was much more dangerous than steel cylinders.

Steel cylinders have pressure gauges and pressure reducing valves, and the risk of explosion is fully considered in the design, and there are also requirements for service life, so it is rare to hear that steel cylinders explode spontaneously.

Ordinary water heating kettles do not have pressure gauges. When the water heating kettle is turned on from the outside, what you are facing is a Schrödinger water heating kettle, just like a "black hole", and no one knows what is inside. Condition.

Therefore, it is usually necessary to let the hydrothermal kettle fully cool down for a long enough time to ensure that the internal temperature and pressure return to normal before opening the kettle body.

Xu Qiu didn't know the details of the master student's accident.

There is a high probability that the kettle was opened in advance. As a result, the pressure inside the kettle body was very high, and the lid popped on.

The problem behind it, although it may be the result of the superposition of many aspects, is mainly due to the general lack of attention to laboratory safety in China.

If, by extension, it means that the country is more pursuing "fast", or "quick success".

For example, some research groups require how long it takes to produce results, and the synthesis reaction must be completed within a few days. If it is not done well, it means that the work attitude is not serious.

Many students have committed suicide by jumping off a building after being repeatedly PUAed by their instructors because they have not experienced strong winds and waves. In order to catch up with the progress of the experiment, it is very possible that they neglected safety.

In fact, in the early days when we were poor and white, we could indeed do this kind of reckless pursuit of rapid improvement and catch up with the pioneers.

But when domestic scientific research develops to a certain level, effective management and safety considerations may become the key barriers to progress.

Just like many industries can grow wildly in the early stage, when they grow to a certain scale, they must be restrained, otherwise there will be a phenomenon that the tail is too big to drop, including a company that tried to intervene in the banking business, and now it has begun to be sanctioned.

After Xu Qiu placed the order online, about half an hour later, the gas supply uncle from the drug warehouse came over with a nitrogen-hydrogen mixed gas cylinder.

The uncle broke a finger, and he didn't know why.

However, his method of transporting the steel cylinder is very skillful. The steel cylinder has an angle of about 15 degrees sideways. When the cylinder is rotated, the cylinder will move forward while rotating.

Uncle Qi arrived at the door of 216, and Sun Wo went to meet him.

Sun Wo is now the person in charge of the laboratory cylinders.

Because the temporary straps used to fix the cylinder were limited, Sun Wo took out the empty nitrogen-hydrogen cylinder and replaced it with a new cylinder.

In fact, if you study carefully, this method of transporting steel cylinders also has potential safety hazards.

The steel cylinder must go up to the second floor, so it must be by elevator.

The air delivery uncle directly supports the steel cylinder and transports it along with the elevator.

The safer way is to arrange for two people to transport, one person is responsible for transporting the steel cylinder to the elevator, and then the person does not come in, press the button corresponding to the floor, and the other person will respond upstairs and take out the steel cylinder.

In other words, let the steel cylinder take the elevator upstairs by itself.

At the same time, during this process, the elevator is temporarily prohibited from being used by others.

This avoids unexpected situations.

For example, if the steel cylinder is about to explode in the elevator, there is no room for people to escape, and they can only watch themselves being blown to death.

However, in practice, if you really pay attention to safety so much, you need to invest a lot of extra costs.

Including publicity costs, cultivating the awareness of students and teachers in this area, and additional labor costs, it is necessary to hire a few more uncles.

In fact, domestic safety education only started to be vigorously promoted around 2015. Before that, there was not even a compulsory "Laboratory Safety Education" course for graduate students.

Including the control of hazardous chemicals, it also started around 2015. Before that, medicines were purchased casually.

Later, it was necessary to go through the process of the school drug warehouse. Precursor drugs such as acetone still need to be reviewed by the department before they can be purchased, and a safety self-inspection form needs to be filled out regularly.

Perhaps, this is the domestic discovery that the previous brutal growth route of the scientific research circle is no longer suitable for the current situation.

However, the process of reform is always very difficult and will encounter all kinds of resistance.

After the introduction of many policies, the resistance to implementation is very high, because the interests of some people will be more or less damaged.

But as long as the direction is right, there will always be a day of success.

PS: Ask for a guaranteed monthly pass.