I Have a Research Support System

This time, the sound came from the glove box next to it, as if something heavy had fallen.

Seeing this, Chen Wanqing shouted: The valve can be closed.

Xu Qiu calmly tightened the valve.

In fact, he had already been mentally prepared. When he was trying to open the hatch just now, he noticed that the hatch was actually hanging in mid-air.

Because the evaporation chamber is in a vacuum state, there is a pressure difference between the inside and outside of the chamber, so the door will not fall down. Now that the cabin is filled with nitrogen and the internal and external pressures are the same, the hatch will naturally fall to the track below and make a crashing sound.

The only thing he is not sure about is the specific time required for the evaporation chamber to be filled with nitrogen, after all, it is the first operation.

But in order to cooperate with his senior, he still turned his head and pretended to be surprised.

Seeing the appearance of the senior sister's plan succeeding, Xu Qiu followed the trend and asked: Senior sister, what's going on? The equipment is broken, right?

Chen Wanqing explained with a smile: After the vapor deposition cabin is filled with nitrogen, the hatch will pop out. It was the sound of the hatch hitting the track just now.

So that's how it is. Xu Qiu suddenly realized.

Now that the performances have been performed, let's perform a full set.

…………

Xu Qiu entered the glove box, opened the hatch, took off the sample holder, and used tweezers to clamp out the 11 substrates on the holder one by one, and put them into a petri dish.

He randomly picked up a piece of substrate to observe, and found that there were six shiny silver aluminum electrodes on the surface of the substrate.

Unlike aluminum products seen in daily life, the surface of aluminum will not be oxidized in a nitrogen atmosphere, so it is not much different from silver in appearance.

Senior sister, why are there six electrodes deposited by vapor deposition? Xu Qiu wondered.

Because a mask is used in the evaporation process, Chen Wanqing explained: The mask is a stainless steel sheet with a hollow pattern on it, and it is placed under the sample stage. Only in the hollowed out part can the target molecules pass through. In this way, a specific pattern can be obtained by vapor deposition on the substrate.

As for why there are six electrodes, it is because six battery devices are integrated on this substrate, and each set of electrodes corresponds to a battery.

To make a simple analogy, you stretch out the index fingers of your left and right hands, cross them, and there will be a square overlapping part in the middle.

The battery device is also similar. The lower ITO electrode and the upper aluminum electrode are like two fingers. Only where they intersect is the effective area of ​​the battery.

The area of ​​the active area must be determined so that we can accurately calculate the photoelectric conversion efficiency of the battery device.

For a substrate like ours, the width of both electrodes is 0.3 cm, so the effective area of ​​a device is 0.09 cm2.

Suddenly, Chen Wanqing seemed to have thought of something, and said eagerly: Xu Qiu, quickly bring the substrate and show me the back of it.

Xu Qiu didn't quite understand what the senior sister wanted to do, but she did it anyway.

After Chen Wanqing observed the substrate carefully, she said, One more.

After reading it, the senior sister breathed a sigh of relief and asked, When you put the substrates, did they all face the same direction?

Yes. Xu Qiu said.

When he placed the substrate, he noticed that the ITO pattern on the substrate was 180-degree symmetric instead of 90-degree symmetric. But he didn't think much about it at the time, and directly operated according to the system's image.

That's good, Chen Wanqing said: The substrate must be placed in a specific direction. As I said just now, after the two electrodes cross, the overlapped part is the effective area of ​​the battery. If this batch If the substrate is rotated 90 degrees and evaporated, the ITO and the ends of the aluminum electrodes will be directly connected, and the battery will be short-circuited.

That's not right, Chen Wanqing said doubtfully, I never taught you this, how did you know that?

Xu Qiu was taken aback, that's right, I didn't even know the mask template just now, so I can't say that I analyzed it myself.

Since it doesn't make sense, I can only make up a reason.

The first substrate, I just put it on at random, and then I thought that this batch of substrates can be regarded as a family, so they should be neat and tidy, so I simply placed them in the same direction. Xu Qiu said with emotion. road:

Unexpectedly, there is a 50% probability that I hit the right one. It's really lucky.

Is that really the case?

Of course.

at this time.

Xu Qiu thought to himself, fortunately, the senior sister didn't get entangled in this problem any more, and managed to get away with it.

Chen Wanqing thought to herself, this is called pre-emptive diversion of attention, my junior didn't notice at all, and I missed the details of the experiment again.

…………

Chen Wanqing looked at the time on her phone, it was 4:56 pm, and said:

There is more than half an hour to eat, let's install the next batch of zinc oxide substrates, it should come in time.

Xu Qiu thought about it and asked:

Doesn't evaporation take more than two hours?

You can go to eat during the vacuuming time, and you can continue after eating. Chen Wanqing said.

What about the instrument? Xu Qiu wondered, Don't need someone to watch it? What if something breaks down halfway?

Theoretically, when a large instrument is in operation, someone needs to watch it, but our instrument is not dangerous, and an alarm will be issued if the instrument operates abnormally.

So just let Wu Feifei watch outside, she has to rush to write the article, and Teacher Wei said that she will submit the article next week, so she is urgent. After we go to the cafeteria and finish our meal, just pack a copy for her. Chen Wanqing explained.

Xu Qiu nodded and continued to work.

The device structure of the second batch of substrates is Glass/ITO/ZnO/P3HT:PC[60]BM:PC[70]BM/MoO3/Al.

Therefore, it is necessary to vapor-deposit molybdenum trioxide and aluminum, the former is vapor-deposited by beam source furnace, and the latter is still heated by electric current.

Xu Qiu installed 10 substrates with sample holders, put them into the sample stage, added molybdenum trioxide powder in the beam source furnace, hung the tungsten basket full of aluminum ingots, closed and tightened the hatch.

Then turn on the mechanical pump and open the ultra-vacuum damper valve.

When the vacuum degree drops below 20 Pa, close the ultra-vacuum damper valve and start the molecular pump.

Done, call it a day.

…………

On the way to the cafeteria.

Xu Qiu, Chen Wanqing, Duan Yun, and Tian Qing chatted as they walked.

Xu Qiu just took this opportunity to get to know other members of the research group.

Senior Sister Tian Qing, did you answer that the illustrations on the PPT were drawn by yourself?

Yeah, the drawing is not bad, I drew it with a digital board.

Yes, it looks like you.

I also think that I will draw one for you when I have time.

...

Senior Brother Duan Yun, why is your research direction focused on thermoelectricity, while the rest of our group are doing optoelectronics?

I have been working for more than three years after graduating from a master's degree, doing 3D printing and thermoelectricity.

Suddenly one day my brain twitched and I wanted to study for a Ph.D.

It just so happened that our boss met Mr. Wei and recommended me, so he continued to work in the thermoelectric field.

...