I Have a Research Support System

how did you do it?

I chose a lot of courses in my freshman and sophomore year. Han Jiaying said:

I took more than 60 points in the freshman and two semesters, and I got more than 50 points in the sophomore year.

He is a ruthless person, I admire him.

The school stipulates that a maximum of 32 credits can be taken per semester.

Generally speaking, if you choose courses up to 32 points in the semester, if you listen carefully to each class and study the questions carefully after class, in terms of learning intensity, it is no less than re-reading the third year of high school.

Of course, with so many students in each class, there will always be several such fierce people. He didn't expect to meet one here.

In a small laboratory, two characters, Wolong and Fengchu, unexpectedly appeared at the same time.

...

In the evening, if you want to prepare a batch of devices, you will definitely not have enough time, unless it is in a simulation laboratory.

After thinking for a while, Xu Qiu decided to try the true hot spin coating method first, prepare a batch of sample films, and test their light absorption spectra.

Not only can you verify whether the light absorption performance is related to the processing temperature, but you can also practice your hands by the way.

Xu Qiu got up and walked into the laboratory, put on his lab coat, and entered the spin-coating glove box.

It seems to be followed by a small tail.

Glancing out of the corner of her eye, it was indeed Han Jiaying, and she followed behind him silently.

Come as you want.

Xu Qiu didn't say anything, and started to check the remaining solution in the glove box.

There is still about 800 microliters of the previously prepared P2FBT4T-2OD:PC[70]BM chlorobenzene solution, so there is no need to make it again.

The solution is placed on a heated stirring table heated at 90 degrees Celsius for heating.

The solution is done, and the glass slides are also prepared.

The glass slides used in the laboratory are medical slides directly obtained from the drug warehouse, and the length and width of each piece are about 7.5 cm and 2.5 cm.

Before use, it needs to be divided into three with a glass knife to obtain a square slide with a side length of about 2.5 cm.

In fact, many items in the experiment are doing non-jobs.

For example, petri dishes, originally used by biological researchers to cultivate microorganisms, are now used by them to place substrates.

Because a large number of square glass slides are used, Wu Feifei bought a special glass cutting workbench on Taobao before, which can cut many pieces in batches at a time.

Xu Qiu took the workbench with the glass knife out of the toolbox, put it flat on the experimental bench, and stacked three glass slides on it, and with three squeaks, nine square slides were obtained.

Do the same, and get nine pieces again.

A total of eighteen tablets were obtained, which should be enough.

Xu Qiu used it to clean the support and box of the substrate, and was about to clean the glass slides in a box.

At this time, Han Jiaying who was following behind took the initiative and said:

Brother, let me help you.

The sudden voice startled Xu Qiu, and he looked back.

The junior girl had already put on her lab coat and gloves at some point.

After stabilizing his mind, he passed the glass piece over:

This one doesn't need to be cleaned with soapy water, and the ultrasound time can be shorter.

Xu Qiu murmured in his heart, no wonder people want to be big brothers.

It feels really good to have a little brother to help.

...

At around 7:30 in the evening, others returned to the laboratory one after another.

Except for Tian Qing, Duan Yun and the others all arrived a few minutes earlier, only she arrived ten minutes later.

Xu Qiu greeted Chen Wanqing and Han Jiaying, and they entered the laboratory together to prepare for spin coating.

At this week's group meeting, Teacher Wei set the main theme, and Xu Qiu was given priority in all experiments, so no one competed with him for the glove box.

Of course, the main reason is that Wu Feifei is writing articles by hand and has no time to do experiments.

Xu Qiu went into the glove box, and there were two big guardians standing beside him.

Skillfully pick up three pieces of cleaned glass and put them on the heating table for heating.

This spin coating is mainly to investigate the difference between the pseudo-thermal coating method and the true thermal coating method, as well as the light absorption spectrum of the effective layer film under different heating temperatures.

The heating temperature was set at 90°C and 120°C.

Two spin-coating methods, two temperatures, a total of four conditions.

Xu Qiu turned on the spin coater, set the parameters, and planned to try the pseudo thermal spin coater first.

The operation went smoothly without any surprises.

The following real hot spin coating mainly tests his hand speed.

Xu Qiu holds a pipette in his right hand and tweezers in his left.

First unscrew the bottle cap on the vial containing the solution, insert the tip of the pipette into the bottle, absorb the solution, and keep this state without taking out the pipette;

Then quickly pick up a piece of glass on the heating platform, transfer it to the platform of the spin coater, and then turn on the spin coater. The whole process time is controlled within 3 seconds;

Then take out the pipette gun, aim at the glass substrate, and quickly spray the solution inside it on the high-speed rotating glass slide, and the time should also be controlled within 3 seconds.

Finally, cover the bottle cap of the solution bottle to prevent the solvent from volatilizing in large quantities and causing changes in the concentration of the solution.

The whole process is smooth and flowing.

Spin coating is completed within five seconds after the substrate and solution leave the heating environment, so that the temperature during the film formation process can be maintained to the greatest extent.

This operation is too fast. Han Jiaying exclaimed.

Chen Wanqing was thinking, if it was her who operated it, she would definitely not be able to do it so smoothly.

However, in order to preserve her dignity as a senior, she remained silent on the surface.

The two people next to them were full of inner activities, Xu Qiu remained unmoved and continued the experiment.

According to the experimental conditions of the two pieces he had just painted, he painted two more pieces repeatedly.

The operation of the true hot coating method is very difficult, and you must concentrate very much. Otherwise, if you lose your mind and there is a problem with any step of the operation, the experiment will be declared a failure.

If you are excited and knock down the solution bottle that is not tightly capped, the consequences will be even more serious.

Afterwards, Xu Qiu heated the heating stage to 120 degrees Celsius and spin-coated four samples again.

A total of eight samples were obtained.

Brother, why is there a circular pattern in the center of the spin-coated film? Han Jiaying asked now that she was familiar with it.

In fact, Xu Qiu discovered this phenomenon a long time ago:

On the thermally coated substrate, a circular pattern can be clearly seen in the center, which is slightly smaller than the inscribed circle of the square substrate.

The film inside the circle is uniform, while the film outside the circle is darker, indicating a relatively thick thickness.

However, this has no effect on battery device testing, because the effective areas of illumination are all in the circular area.

He also discussed this issue with Chen Wanqing, but did not get an answer.

I don't know the specific reason, Xu Qiu told the truth:

I infer that it is mostly caused by the uneven heating of the solution during film formation.

The temperature of the solution and the substrate is very high, and it is difficult to maintain this temperature in an external environment of normal temperature, and the temperature will gradually drop.

However, the solution diffuses from the center of the substrate to the surroundings, so the film is formed in the center first, and then in the surrounding area.

Assuming that the rate of temperature decrease in the center and the surrounding area is the same, then the film forming temperature will be lower in the surrounding area where the final film is formed.

This may be the reason for a circular pattern in the center of the film.

I think what brother said makes sense, Han Jiaying said.

I also think it's the reason, Chen Wanqing said:

However, it is not meaningful to entangle this kind of problem. The problem of changing the spin coater with heating will be solved.

Thanks to fireworks ck and Lan Shiyu for rewarding 500 starting coins, and ych Eagle Flying World for rewarding 100 starting coins.