Chapter 754 Gao Zhendong, who loves the sea
Just when everyone was relieved, a young voice suddenly rang out.

"This battery is not usable. It needs to be replaced."

Who is this? Just listening to the introduction, you say it can't be used? It's too unscientific.

When people turned to look at the speaker, their thoughts changed a little.

Is it really not usable?

——The person who spoke was Gao Zhendong.

Gao Zhendong has already proved one thing before, that is, when it comes to optoelectronic materials, he has not just one brush, but many brushes.

Even if the photoelectric materials of the camera tube are different from those of the solar panel, it is always true that they are of the same origin. Not to mention, some comrades also remembered one thing.

The world's first laser beam was created by a man named Gao Zhendong. Although the possibility of a person with the same name cannot be ruled out, judging from the current scientific research environment, talent distribution, and profession, it is most likely this person.

Everyone looked at Gao Zhendong, waiting for his explanation.

"Although N-type substrate solar cells have high conversion efficiency, they have a fatal flaw. They are fine for use on the ground and in the sky, but not in outer space."

When the leader mentioned N-type substrates, Gao Zhendong suddenly remembered that he had processed a batch of single-crystal silicon wafers with N-type substrates for external system units. It must be this batch, because it was one of the few silicon wafers processed for units outside the 12th Ministry of Machine Building since the birth of single-crystal silicon.

Combining the quantity and doping type, Gao Zhendong easily determined the destination of this batch of silicon wafers, which was to be used in solar panels.

It turns out that they are used to make P+/N type solar cells with N type substrates. Gao Zhendong has something to say about that.

In his previous life, he started working on telemetry systems with his teacher as a junior, so he had a relatively deep understanding of solar cells. There was nothing he could do about it, because the tutor was capable, but his requirements were also really high. That's what he said.

——"This is just a training project for you. It's not a serious project, but if you want to practice, you have to master all the relevant knowledge. The telemetry system itself is not important. What's important is that you have to master the basic knowledge of all aspects of the telemetry system through this small project and prepare for bigger projects."

Solar panels are the most common power source for telemetry systems, if not the only one. Gao Zhendong naturally put a lot of effort into understanding them. He had to do this, as his supervisor was really good at scolding people.

Therefore, Gao Zhendong knew very well what would happen to the solar panels with N-type substrates when they were put into space. This was also the reason why the solar panels developed for the second satellite in the previous life were changed in the middle of their journey.

"What flaw?" Seeing that Gao Zhendong used the adjective "fatal flaw", everyone knew that this matter was probably set in stone and could not be changed.

Gao Zhendong looked at the leader of the Defense Work Committee: "Can you tell me?"

The leaders of the Defense Work Committee knew that the silicon wafers for this batch of boards were processed by Gao Zhendong. At that time, it was the only company in the country with such production capacity. Even now, there are not many companies with such production capacity. Therefore, Gao Zhendong should be aware of the situation and have his own opinions. He asked himself this question, just to confirm whether he could say that the processing of this batch of silicon wafers was done by him.

"Go ahead, there's nothing wrong with the comrades here."

Gao Zhendong nodded. "This batch of silicon wafers was processed by us. After processing, there are some necessary tests. During the test process, combined with theoretical analysis, I found that the conversion efficiency of P+/N-type solar cells with N-type substrates will decay rapidly in a high-energy radiation environment. In other words, this type of solar cell will die faster in space."

Up to the time period that Gao Zhendong knew about, not only ours, but all aerospace solar cells in the world were N+/P-type cells with P-type substrates. This is the reason.

Gao Zhendong's statements were mixed up, and this kind of test was definitely not conducted. But no one knew that. He then added the words "combined with theory", so others would not know whether he discovered it through testing or through theory. Even if it was finally discovered that the Third Rolling Mill did not conduct this kind of test at all, it could still be attributed to theoretical analysis.

As for theoretical analysis, no one can doubt Gao Zhendong. As a top expert in optoelectronic materials, if he says there is a theory, then there is a theory.

Gao Zhendong really worried about how to express this issue reasonably.

When the comrades heard this, they realized that the fatal flaw Gao Zhendong was talking about was not an adjective, but a description of the facts.

——Fatal (Physical).

No one doubted Gao Zhendong's words.

"Rapid decay is really fatal." "Yes, that's right. It doesn't need to decay to 0. As long as it decays below the design power requirement, the battery will be starved to death. An unhealthy charging process is also fatal to the battery."

"I only knew that P+/N was highly efficient, but I didn't expect it to have this problem."

This cannot be blamed on the comrades who did the preliminary work. This kind of problem either needs to be studied in depth or tried in space, otherwise it cannot be discovered. Up to this point, we do not have the conditions for both. In this case, the advantage of P+/N solar cells in slightly higher efficiency under the current technological environment is reflected.

"Moreover, 7% is too low an efficiency. Even if it reaches 10%, it is still not very good. It places too high a requirement on the weight of the solar panels that the satellite needs to carry, affecting the actual mission payload weight of the satellite."

No, what you said is too much. To reach 10%, it is only possible because of the efforts of our comrades. How can you deny it with just one sentence?

Hehe, hahaha~~~~~~
Unlike other comrades, the members of the Defense Work Committee probably felt this way. They were not angry at all, but very happy on the contrary.

Before the Defense Work Committee spoke, a comrade raised doubts: "Comrade Zhendong, 10% is not enough? And this is the efficiency of the more efficient P+/N solar cell. If it is replaced with N+/P, I am afraid it will not reach this efficiency, right?"

I am not questioning the replacement of solar panels, but the statement that the efficiency is 10% lower is a bit of a way out. In detail, it is also a kind of care from the predecessors to the younger generations. They even have a reason for it, that is, changing N+/P is naturally low.

At this time, Gao Zhendong no longer cares about keeping a low profile. As a young man, he still needs to be aggressive. I think these old seniors won't mind.

"It's like this. When I was producing that batch of P+/N solar panel substrate silicon wafers, I also studied some related content and gained some experience. I feel that the efficiency of solar cells is not only a problem of the optoelectronic basic materials themselves, but also the overall structure of the solar cell is also very important, including some optical aspects. I conservatively estimate that if the design is proper, coupled with the optimization of optoelectronic materials, even N+/P solar cells will have an efficiency of no less than 15%, which is basically the same as the current level of Citigroup."

It was indeed like this. Gao Zhendong's habit was never to just raise questions and then leave after a while. Instead, he would raise the questions and also come up with solutions. If there was no detailed solution, at least there was a technical route. If there was no time even for the technical route, at least he could come up with an idea that seemed feasible.

Read the error-free version at 69shuba! 6=9+shu_ba is the first to publish this novel.

The leaders of the Defense Work Committee were all beaming with joy. With such capable people in their midst, there was no need to worry about not accomplishing great things!
However, Gao Zhendong's words still caused quite a bit of impact on other seniors, 7% to 15%!

Your "by the way" is a bit too profound. Few people can "by the way" improve the core parameters of a product by more than double, and they have to change the technical route and use technology with more inferior principles to achieve it.

It was the first time that Gao Zhendong officially appeared in front of these top masters. This first time gave them a great shock. This young man was incredible.

"12, 12% will be fine." The leader of the Defense Work Committee said happily. This kind of talent must be protected and used. If you don't lay an ambush, I will do it for you.

In fact, what he didn't know was that Gao Zhendong had already set an ambush by raising the 15%.

Seeing that the leaders of the Defense Work Committee did not even question or ask any more questions and directly confirmed the matter, some of the old veterans became anxious.

"Leader, this... should we be more conservative?" It goes without saying that this young man's technical skills are extremely high. The more so, the more we need to protect him. This is not some cabbage grown in the field.

The leader knew what they were worried about and smiled and shook his head: "It doesn't matter, I know what I'm doing. 10% is the target, and we'll try to reach 12%."

The veterans were relieved at this point. In fact, what the Defense Work Committee leader had in mind was completely different from what they were thinking. The leader knew very well that when Gao Zhendong said 15, then the probability was 15. He dared to guarantee that if this thing was really developed, it would definitely be around 15% and would not be much lower.

He knew Gao Zhendong too well. This guy sometimes looked radical, but he was actually very stable!

"If we can really reach 12%, there will be a lot more places where we can use it. Hahaha, there were some places where it was inconvenient to get electricity before, but now we can also carry out related work."

"Yes, in fact, 7% can do a lot of things. With the battery, it can provide a relatively stable power supply for a long time."

In fact, the attenuation of solar panels on the ground is not as serious as the legend says. my country's first 10kw photovoltaic power station was built in 83. 40 years later, it still has a power of about 7kw. However, the solar panels of this power station were donated from abroad. The Japanese were indeed good at this at that time.

Gao Zhendong smiled and said, "Yes, for example, at sea or on an island, it can at least provide basic electricity and communication guarantees for daily life. It can also be used for unmanned automatic monitoring in some places with difficult conditions."

Speaking of this, he was no longer sleepy, because this was his first subject in his previous life, and he could master it easily.

On the islands and reefs, as long as the basic electricity needs for living and communications are met, people can be kept there. Air conditioning may not be available for the time being, but at least it will be okay to bring an electric fan, right?

Everyone in the Defense Work Committee laughed in their hearts, Comrade Gao Zhendong still "loves" the sea so much.

(End of this chapter)