Chapter 319 Cadmium Mercury Telluride, Startup
“Okay, we will do this according to our conditions. Director Gao, what is this Vaseline used for?”
“This is used for The ones that reduce internal friction during processing are considered process additives.”
The two discussed the plan for a while, and Mr. Luo was simply amazed by Gao Zhendong’s “know-it-all” characteristic: "Director Gao, you are very familiar with energetic materials."
Gao Zhendong chuckled: "I just know a little bit about it. It's a pity that the commission doesn't let me do more, so I can only do this. Planted.”
Listening to these words, Mr. Luo's forehead hurts. Wei Li will definitely not let you do this anymore.
As for the production process of this propellant, it is a combination of more traditional energetic material processes, and compression molding. When it comes to this, Mr. Luo understands it better than Gao Zhendong.
The two had another exchange on the process. Mainly Gao Zhendong made the request, and Mr. Luo confirmed whether the conditions were met. If the conditions were not met, he had to make relevant preparations.
This involves many processes including absorption, mixing, water displacing, calendering, drying, and stretching. Gao Zhendong and Mr. Luo communicated and confirmed one by one. There is quite a lot of content, and Mr. Luo also feels overwhelmed. Although the processes are the same, the specific process parameter selections are different.
While communicating with Gao Zhendong about craftsmanship, I can learn a lot of extended knowledge related to these crafts. After all, what Gao Zhendong comes up with is a bit advanced, and it can also be of some use to the Changjian Factory. The effect of drawing inferences from one instance and drawing analogies is very useful.
Although it is included in these plans, it is equivalent to a technical briefing. Looking at the materials is never as full and direct as communicating in person. Otherwise, everyone can just study by themselves with the textbooks. What kind of teacher is needed? The plan only states what to do. Do it, but why do you do it? You have to communicate with the designer in person to understand the trick.
Mr. Luo looked at his thick notebook with many pages and smiled broadly. Only when you do things with capable people like Mr. Gao can you achieve both results and ability. study.
After seeing Mr. Luo off, Gao Zhendong packed his things and went home. But it wasn't Children's Day yet, so he wasn't going to give Children's Day gifts to Lou Xiao'e yet. He said he was celebrating Children's Day, and that was Children's Day.
——
Yu Yuncheng sat in front of Gao Zhendong, happily. From May Day to now, it took several weeks to finally wrap up the affairs at 1761 Institute. This made Yu Yuncheng a little impatient.
After all, knowing that there is a good thing in front of him, he must not be able to help it. However, the monocrystalline furnace and monocrystalline silicon are a big deal for the 1761 Institute. This makes him, the responsible person of the 1761 Institute, People have to spend a lot of time arranging and handling the affairs in the house.
Finally all these matters were taken care of. He immediately took a few key members and rushed to the capital in a hurry.
The leader of 1761 asked him why he went to Beijing again. Yu Yuncheng said: "Director Gao of the third rolling mill has a new project and he wants to continue cooperation. And he said that although they are still in charge of this project , he will also apply for relevant resources, but he will not do it in the third rolling mill, but will come to our institute to implement it.”
The leader of 1761 Institute drove people away without saying a word: “Then go quickly, go quickly,” Stop wandering around in the institute.”
It is self-evident that the project can be implemented in the institute.
Now Yu Yuncheng is here with Gao Zhendong, looking for a project.
Gao Zhendong was also very happy when he saw him. The matter of mercury cadmium telluride fell on him.
Although the preparation of mercury cadmium telluride crystals and offline scanning thermal imaging cameras are still some way off, without this first step, the rest goes without saying.
As for indium antimonide not being considered, the main reason is that cadmium mercury telluride can change its bandgap characteristics by adjusting the composition and doping. In layman's terms, cadmium mercury telluride can be detected in the near infrared. , mid-infrared, and far-infrared multiple bands have good photoelectric properties.
And this thing has good radiation resistance. To put it bluntly, it can be used in outer space, aerospace, and nuclear environments.
Although it is relatively difficult to prepare mercury cadmium telluride, indium antimonide is not much better these days. It is troublesome anyway, so it is better to try cadmium mercury telluride first. Anyway, Gao Zhendong has a whole article on tellurium. Preparation of mercury-cadmium crystals.
Looking at him, Gao Zhendong smiled and said: "Old Yu, you are finally done."
Yu Yuncheng smiled sheepishly: "The cleanup of the single crystal furnace in the institute is relatively small. "It's a little delayed."
Gao Zhendong shook his head: "For such a big thing, the related matters are more normal, not in the way."
Yu Yuncheng smiled. : "Anyway, it's done. Director Gao, what are you going to do this time? I've left my manpower behind and said hello to the institute. The institute will fully cooperate."
Gao Zhendong nodded: "Let's make cadmium mercury telluride crystals!"
When Yu Yuncheng heard this, he was stunned. To be honest, he didn't know what cadmium mercury telluride was. This thing was only discovered in 1959. It was created. At this time in China, basically no one knew what it was. "Cadmium mercury telluride? What is it?" Even he was not sure whether it was cadmium mercury telluride or chromium mercury telluride.
Gao Zhendong took the pen and paper and wrote down the chemical formula HgCdTe, which is not a chemical formula. Only then could Yu Yuncheng confirm what Gao Zhendong was talking about, but this thing is used He still had no idea what to do.
Gao Zhendong continued to introduce the characteristics of mercury cadmium telluride material. Yu Yuncheng became more and more excited as he listened. This is a very good optoelectronic semiconductor material, and it has a wide band coverage and good performance structure. It’s stable, and it’s really fun to make this thing.
But he was a little scared. He knew nothing about this thing.
"Director Gao, is this thing good? Can we do it?"
Gao Zhendong smiled and nodded: "I am still somewhat certain. I have already based it on its structure and properties. , composition and other principles, starting from the perspective of metallurgy and crystal phase, I have explored a preparation method, and I am still somewhat certain. At least it is no problem to obtain the compound first. As for high-quality crystals, I am also certain. "
Gao Zhendong’s words made Yu Yuncheng’s hair stand on end. Is it a hard calculation based on principles? Where does the principle of this thing come from? If you didn't say it existed, none of us would have thought that it existed. Infrared detection is still competing with lead sulfide. How do you calculate it?
However, he knew that Gao Zhendong never talked nonsense. From the beginning, the monocrystalline furnace did not seem like it could be developed, but the facts are there, and now he is giving 1274 every day. The factory is pulling raw materials, and at the same time, it is also producing single crystal furnaces non-stop to expand production capacity.
What he didn't expect was that Gao Zhendong not only knew about the existence of this thing, he also had its lattice constant, density, Te-Cd-Hg ternary phase diagram, HgTe-CdTe pseudo-binary phase diagram, and a relatively accurate segregation coefficient. , thermal properties, mercury vapor pressure, electrical properties, etc., a series of data and results obtained over ten years and decades later.
Let's put it this way, even the inventor of HgCdTe in 1959 did not have as complete and accurate information as Gao Zhendong.
Although I don't know where Gao Zhendong's confidence comes from, he is not a fool. There is no need for Director Gao to make fun of him. He did not hesitate: "Director Gao, you can do whatever you say."
Gao Zhendong smiled: "Okay, but you have to be mentally prepared for this. It can't be done in a day or two. The whole process is very long. A test may take several months or even half a year. Done. ”
Due to mercury vapor pressure and other reasons, the crystal growth of mercury cadmium telluride is very difficult. Whether it is a bulk crystal or a thin film crystal, although there are many methods, they are quite troublesome, not to mention the slow crystal growth. , and annealing and other processes require high requirements and take a long time, which can take dozens of days.
This makes the whole experiment very time-consuming and cannot be carried out unless one is determined and perseverant.
For this, Yu Yuncheng doesn't care. The longer the time, the longer it will be. Besides, Director Gao may have a high level of vision, so he has a high level of vision.
In Yu Yuncheng’s view, it’s not a problem to conduct an experiment once every six months. Let alone producing crystals for this kind of thing, it is a major breakthrough to first produce compounds and prove something.
So when working with Director Gao, although the achievements are high, the pressure is also high.
“Director Gao, don’t worry about this, we can still endure loneliness.”
Gao Zhendong nodded. In fact, they didn't have to worry too much. Gao Zhendong was very particular about the choice of preparation method. He chose the one with the simplest process, the lowest equipment requirements, and low temperature control requirements. The most important thing was Yes, there is no need for the most troublesome thing, the crystal growth control mechanism.
However, the crystals grown in this way have uniform composition and good structure, and can be used in the production of detector-level components, and the crystal utilization rate is very high.
Of course, this thing is not without its shortcomings. The crystal diameter is small, there are many high-temperature defects, impurities are not purified, etc., but these are not problems at this stage.
The diameter of the crystal is small. I do line scanning. I just need to make it longer. I don’t need a circular plane.
As for why Gao Zhendong quickly chose this method, the reason is relatively simple. This thing will be the most important crystal growth method for Citigroup's mass production of mercury cadmium telluride detection elements in the next few decades.
I have to say that Citigroup Selection is trustworthy in this regard.
However, at this time, it is not time to come up with all the methods. The first task now is to get the project approved.
Seeing that Yu Yuncheng did not hesitate, Gao Zhendong did not drag his feet and immediately handed him some materials: "That's OK. You first write a research application based on these materials. We will send it to the ministry and follow the instructions. It has been agreed in advance that our two units will join forces, and the third rolling mill will take the lead. As for the specific methods, there is no need to write them down. The ministry should understand."
(End of this chapter)