I Have a Research Support System

Yang Qin led the crowd into the organic laboratory, pointed to the instrument in the fume hood from a distance and said, "This is the scratch coating instrument we designed."

Seeing the instrument directly placed in the air, Xu Qiu suddenly said: "It turned out that the device was prepared in the air, so it is understandable that the performance of the device is low. The PCBM system is still relatively sensitive to air."

Yang Qin explained: "I originally wanted to put it in the glove box, but now this scraping instrument often breaks down, so it's easier to repair it outside."

Xu Qiu suggested: "I suggest you try the non-fullerene system. The stability of several non-fullerene systems developed by our group is good."

Yang Qin asked: "Is there any recommended system? I was doing OFET before, and I don't know much about organic photovoltaics, especially the latest work. I left school and have no campus resources. I want to download documents. Very troublesome."

Scientific research institutions such as universities will purchase the genuine reading rights of major academic journals. Therefore, during the school period, as long as you log in to the campus network, you can directly download most of the literature. If you leave the school and want to download literature, if you pay for it yourself, An article costs dozens of dollars.

Of course, there are ways that don’t cost money. For example, you can send a letter directly to the corresponding author of the article, and the other party will most likely give it to you, but you don’t know when the reply will come, or you can ask a junior student who is still in school to do it for you. download. In addition, journals also have pirated websites, but many people don't know it, and it is not good to use pirated websites after all.

Xu Qiu thought about it for a moment, and said, "It's simple, you just go to 'Madu Comprehensive University Wei Xingsi', and then go to the homepage of our research group, in the column of academic achievements, just look for papers with 'Qiu Xu' in their names."

"All right, I'll go and see later, Qiu Xu..." Yang Qin realized, "You are Xu Qiu, right, I heard Lan He talk about you before."

"That's right, it's me," Xu Qiu added, "If materials are needed, our team can also provide them, but we still need Lan He to talk to our instructor about how to do it."

"Okay, I'll tell Lan He about the situation later." Yang Qin nodded, then pointed to the fume hood and said, "Let me introduce our scraping equipment to you first."

"The current structure of this set of instruments is relatively simple.

"The first is a sample platform, on which the substrate can be placed, and has a fixing device, and the bottom is a heating device, which can provide a certain temperature and ensure the fluidity of the solution.

"On the side of the sample platform is a track, on which there is a cantilever that can move back and forth, and a razor blade is embedded in the lower end of the cantilever.

"The cantilever is connected to a controller that controls the speed at which the blade moves and the distance between the blade and the substrate.

"When the instrument is working, the cantilever with the blade slowly moves from the position where the solution is dripped from one side of the substrate to the other side, and the scraping operation is completed."

Xu Qiu nodded, what Yang Qin said was similar to what he had made up based on reading the literature.

However, judging from the current situation, Lan He and Yang Qin still have a long way to go, at least in terms of process improvement, there is still a long way to go.

On the one hand, the scraper uses a razor blade, which is fine in the initial use, but will definitely use a micro-nano processed blade in the future, so as to achieve accurate thickness;

On the other hand, the devices they scrape-coat now are small-sized devices of 1 cm * 3 cm, and they cannot take advantage of the advantages of scraping coating, and they will still develop to larger sizes in the future.

These are two relatively obvious problems. If we dig deeper, other problems will emerge.

For example, what material is used for the scraper, metal, ceramic, or other materials?

For another example, if we want to develop to a large size, should we increase the width of the scraper, or keep the width of the scraper unchanged and scrape back and forth repeatedly?

Of course, these questions must be known to Yang Qin and the others. After all, he is a Ph.D. student from Shanghai Jiaotong University, his friend school, so he must have basic research and development capabilities.

Therefore, Xu Qiu didn't mention it. After all, he came here as a guide, not to personally develop instruments and research techniques.

Xu Qiu feels that his main strengths lie in his understanding of the field of organic photovoltaics and the development of a large number of new materials. Next, he can give opinions mainly from these two aspects.

At this time, Yang Qin handed over several gas masks to Xu Qiu and the others, and said, "Let me show you the scraping process. The gas masks are new."

Han Jiaying retorted casually: "I haven't used the 'pig nose' for a long time, I didn't expect to use this here."

Yang Qin explained: "There is no way, the solvent is chlorobenzene, and a few milliliters of solvent is used every time. I only use a fume hood here, and I am afraid that the smoke will not be clean."

Xu Qiu continued: "Speaking of this, I suggest that you develop non-fullerene materials. Some systems can be compatible with non-halogenated solvents. Solvents with chlorine atoms such as chloroform and chlorobenzene are not only highly toxic to the human body , It is also very harmful to the environment. In the future, you can consider switching to tetrahydrofuran THF, so you don’t need to wear a gas mask.”

Yang Qin nodded: "Okay, I'll try it later, the smell of chlorobenzene is indeed too strong, and it will also be adsorbed on clothes."

In fact, Xu Qiu had tried various solvents in the simulation laboratory before.

Generally speaking, solvents with chlorine atoms such as chloroform and chlorobenzene are indeed more effective, but some systems use THF, which can also show good device performance, but Mr. Wei uses a glove box to operate. It is too good to change the solvent atmosphere rashly, because there may be unknown effects.

In many fields, it is one thing in the laboratory, but it is another thing when it is industrialized, and various problems will arise.

For example, if the problem of chloroform and chlorobenzene solvents is not resolved, even if other conditions are corrected, workers must wear chemical protective clothing and gas masks for a long time before they can work during industrial scraping.

And all protective devices have limits, and it is impossible to 100% isolate toxic solvents. If this work is done for a long time, workers will definitely be chronically poisoned.

This is why electronics factories, workers who wear chemical protective clothing and gas masks can earn 1K or 2K more than other types of workers every month.

Without it, health is sacrificed.

After Xu Qiu and the others put on their masks, Yang Qin began to operate.

He first turned on the heating device of the scraping instrument, set the temperature to a constant temperature of 60 degrees Celsius, and then started the heating and stirring table next to it, set the temperature to 60 degrees Celsius, and the rotation speed to 300r.p.m., to stir the PCE10:PCBM and PFN solutions.

Among them, PCE10:PCBM is the effective layer solution, which is packed in a small brown bottle protected from light, and PFN is a polymer transmission layer material developed by Zang Chaojun and Lu Changjun, which is used to replace the traditional PEDOT:PSS transmission layer and construct positive The device of the structure is installed in a colorless and transparent glass bottle, and the solution is also colorless and transparent with low viscosity.

Xu Qiu’s commonly used device structure is an inverted structure device with zinc oxide as the transport layer. Now Yang Qin and his colleagues use a flexible substrate that cannot be annealed at high temperature. It is difficult to use the structure of zinc oxide, so they choose PFN as the transport layer material.

Next, Yang Qin removed the razor blade on the cantilever, replaced it with a new blade, cleaned the sample platform, placed a flexible substrate, and stretched and fixed the substrate with a clamp. The controller regulates the position of the blade, which is approximately 3-5 mm above the sample.

Among the three people who came over, the junior girl paid the least attention to the Blue River Laboratory, and basically came here to join in the fun and have fun, while the senior sister paid the most attention to the situation of the Blue River Laboratory.

"How is this height controlled? Do you rely on visual inspection?" After putting on the gas mask, Chen Wanqing's voice was a little husky.

Yang Qin smiled awkwardly: "That's right, it's just based on visual inspection. I've already suggested that Blue River recruit a programmer to write the control program, and I'm currently interviewing."

Chen Wanqing shrugged: "Okay..."

This is probably the true portrayal of science and technology companies. To a certain extent, science and technology companies are similar to doing scientific research. They are all exploring a relatively cutting-edge field. It is just that science and technology companies are for commercial applications, and the price of failure It is very big, and the probability is very high. If it succeeds, the harvest will naturally be high.

After the temperature of the two heating platforms was kept at 60 degrees Celsius, Yang Qin started the scraping experiment, first with PFN solution.

Using a one-milliliter disposable syringe with the needle removed, he draws up about 200 microliters of solution, squeezes it out onto the side of the flexible substrate, and activates the console.

The blade scrapes slowly over the substrate, driving the solution across the substrate, forming a thin film.

After that, an annealing operation at 100 degrees Celsius is performed to completely evaporate the remaining solution on the film.

The whole process takes a little longer than spin coating. Another problem is that it takes a lot of solution. Normal spin coating only needs 70-100 microliters. If it is spray coating, it only needs 15-20 microliters. Here, scrape coating requires 200 microliters. Lift.

Yang Qin continued to use the same method to scrape and coat an effective layer of PCE10:PCBM.

During the annealing, Chen Wanqing asked: "How to solve the other transport layer and electrode? Is it the whole solution method?"

"That's right," Yang Qin replied: "The other transport layer material is PDINO, and the electrode material is silver nanowires, which are prepared by scrape coating and drop coating respectively." PDINO is a derivative of PDI, which can As a transport layer, it replaces the metal calcium of the positive structure.

"I thought it was evaporation," Xu Qiu continued, "If that's the case, you can achieve 3% or 4% efficiency, which is actually not too low."

"Yes," Yang Qin nodded, "it's just that the performance of the device is a bit unstable."

Subsequently, Yang Qin scraped PDINO and drip-coated silver nanowire electrodes again, completing the preparation of a batch of devices.

Because the full-solution method does not require evaporation, the overall speed of device preparation is faster than that in Wei Xingsi's group. Excluding the operations of solution preparation and substrate cleaning, it only took more than an hour.

After the experiment, the four took off their gas masks, left the chemical laboratory, and returned to the device laboratory. Yang Qin handed over the newly prepared device to one of his colleagues.

At this time, Xu Qiu faintly felt that something was wrong. He counted the heads and found that including Yang Qin, there were six white coats in the room.

Taking a closer look, Lan He actually took part in the experiment himself.

Lan He glanced at everyone and said, "Yang Qin, take them to the office for a while, and I'll come over right away."

"Okay." Yang Qin led Xu Qiu and the others to the office next door, and then used disposable paper cups to help fetch three glasses of water from the water dispenser.

After sitting down, Xu Qiu casually asked, "How long has it been since your laboratory was built?"

Yang Qin thought for a while and said, "It's been more than half a year. I joined the job in the spring. I have been decorating for the first few months. I just finished the device laboratory almost two months ago. After that, I kept trying and failed. , the efficiency just broke 4% until last week, and this week Blue River invited all of you here."

Chen Wanqing's focus is rather unique: "Job entry in spring?"

"That's right," Yang Qin said helplessly, "Over there at Jiaotong University, my tutor didn't let me go, so I postponed my graduation for half a year. By the way, you are all from Shanghai Comprehensive University?"

"Well, let me introduce you," Xu Qiu took the initiative to say, "I'm a freshman of direct Ph. Doctorate three, graduate next year, um, the doctorate in our school is three years."

"Three years, that's great." Yang Qin shook his head and sighed: "Hey, I chose Jiaotong University by mistake at the time. If I didn't have a tough attitude, the supervisor probably would have delayed me for a year."

"Actually, it's pretty much the same everywhere," Chen Wanqing comforted, "Now the professors in our school have heard that they have been jointly giving advice to the school, saying that they want to increase the Ph. "

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