Volume 1: Student Life Chapter 245 Asking for Help
Just when Shen Jing was feeling deeply moved, Chen Zhou came back.
There was also a tall and thin boy wearing glasses.
"Senior, let me introduce you." Chen Zhou pointed to the boy next to him and introduced, "This is my high school deskmate Zhang Yifan, who is from the Chemistry Department of Huaguo University of Science and Technology. I called him to help."
After that, Chen Zhou pointed at Shen Jing and said, "This is senior Shen Jing who came to Luzhou with me to participate in the project. Like me, he is from the Department of Mathematics at Yan University."
"Hello." Zhang Yifan and Shen Jing greeted each other.
"Yifan, come here." Chen Zhou moved the chair and placed it next to the table, then said, "Except the first 47 articles of the literature you downloaded this afternoon, I'll need you to help me sort out the specific process information in the rest of the literature."
"No problem." Zhang Yifan nodded, but then he realized something was wrong. If he removed 47 articles, there would still be...
???
Chen Zhou looked at Zhang Yifan and said with a smile: "I believe you can do it!"
Zhang Yifan: “…”
Shen Jing looked at Zhang Yifan, then moved closer to Chen Zhou and asked softly, "When did you ask him to download the document for you?"
Chen Zhou said: "Before I went to Dr. Wu's office, I called him and asked him to help me find the literature. After all, some of the literature can only be downloaded from the school library."
Shen Jing suddenly realized, and then looked at Chen Zhou deeply.
Hearing what the two said, Zhang Yifan smiled and said, "I thought Chen Zhou suddenly called me for something, but it turned out that he wanted me to help look up documents. I was wondering why you didn't say hello in advance when you came to Luzhou this time?"
Chen Zhou smiled and said, "Didn't I just arrive? Isn't it nice of me to come to you right after I arrived?"
Zhang Yifan did not comment. He estimated that if Chen Zhou had not called to talk about it before leaving, he would have called to talk about it.
But he also understood this, this was not a holiday, it was a mission.
And judging from the situation, it should be a task with a tight time frame.
So after receiving the call, Zhang Yifan didn't say a word and spent the entire afternoon helping Chen Zhou look up literature.
What puzzled him was that Chen Zhou actually wanted so many documents...
Is it true that the more of this stuff, the better?
"I heard that you are going abroad to give an academic report?" Zhang Yifan asked Chen Zhou, thinking of the news he saw on the Internet.
Chen Zhou sat back at the table and flipped through the documents while saying, "Well, on the 15th of next month, I will give a report on the proof of the hail conjecture."
"Great! I thought the news on the Internet was unreliable, but I didn't expect it to be true!" Zhang Yifan was very happy for Chen Zhou.
Chen Zhou smiled and urged, "Hurry up and work. I'll treat you to a big dinner later! You have to go back to school in the evening, so don't be too late."
"Deal!" Zhang Yifan said with a smile.
Then, the two stopped talking and went back to their work.
Shen Jing couldn't help but glance at the two of them. Chen Zhou and Zhang Yifan were both looking at the documents seriously, completely unlike the chatting and laughing they were just now.
"Isn't it too fast to get into the state?" Shen Jing muttered to himself.
He didn't know that Zhang Yifan's study habits were basically developed when he was repeating a grade in high school and was under pressure from sitting next to Chen Zhou.
Not only Zhang Yifan, but also the classmates around Chen Zhou were more or less affected.
As Chen Zhou changed, they were also changing silently.
Chen Zhou assigned the main sorting tasks to Zhang Yifan and Shen Jing respectively, which also gave him time to study more about the entire preparation process of diamond film.
Only with a complete understanding can the preparation method be improved.
Moreover, Chen Zhou did not intend to study the MPCVD method from the beginning.
He plans to be more comprehensive first and then seek a breakthrough.
There has been a change in the method of preparing diamond films.
From the high temperature and high pressure in the 1950s, to the CVD method first used by Japanese scientists in the early 1980s, to today's various synthesis methods.
Although they are said to be a variety of synthesis methods, they are actually all improvements based on the CVD method.
[Preparation of diamond film by hot wire CVD method (HFCVD)]
This document provides a comprehensive introduction to the preparation of diamond films by HFCVD.
Although this method is the ancestor of the CVD method, it is still widely used today and has developed into one of the more mature methods for depositing diamond films.
This method requires setting up a metal hot wire above the substrate, commonly used wires are tungsten wire and tantalum wire.
The carbon-containing gas is then heated to 2000-2200°C to decompose and form active particles.
Under the action of hydrogen atoms, diamonds are deposited on the substrate.
Although this method is simple, its deposition efficiency is very low, much .
Not only that, but the process also has poor stability and is prone to pollution.
Although the literature also mentioned two improvement methods, Chen Zhou also disagreed.
Because the efficiency has been improved, but the quality of the diamond film is still too low.
This is obviously not applicable to the research on diamond semiconductor materials and devices.
However, Chen Zhou thought that the improved method was worth a try.
One is the HFCVD method of reaction gas distribution, that is, the carbon source gas and hydrogen are respectively introduced from the bottom and the top of the hot wire.
The other is the electron-assisted HFCVD method, which increases the deposition rate by applying a bias voltage of about 150V to the substrate.
Chen Zhou reads documents very quickly. Even when he takes notes while reading, his efficiency is far superior to others.
This is also due to the bonus provided by his system subject upgrade.
Before coming here, he quietly upgraded his chemistry to Lv2 just in case.
Therefore, with the bonus of his chemistry subject level, Chen Zhou frantically absorbed relevant chemical knowledge.
Unlike studying mathematics and physics, Chen Zhou does not plan to use the same method to study chemistry and biology.
Chemistry and biology are two subjects that are more inclined towards experiments and applications, so Chen Zhou plans to start with experiments and applications.
With the added benefit of subject level, learn efficiently and explore the unknown through experiments and applications.
Then fill in the unknown by looking up information.
Although this method does not involve a mathematical or physical system, it is very efficient.
And it is very suitable for Chen Zhou now.
After reading three papers on the HFCVD method, Chen Zhou felt that the general ideas were similar, so he stopped bothering with this method.
Instead, he looked at the next method, flame deposition.
This method was first proposed by Japanese scholars, but it was confirmed in a laboratory on the other side of the Atlantic Ocean.
This method mainly involves mixing carbon source gas and oxygen and burning them in the atmosphere.
The burning flame is divided into three zones. In addition to the inner flame and the outer flame, there is also a layer of reducing flame.
The substrate is placed in the reducing flame region of the flame to grow diamond.
The key to this method is the mixing ratio R of acetylene and oxygen.
Diamond can only grow in the R=0.7~1.0 region.
Other areas are not conducive to the growth of diamonds.
"R = 0.97 to 1.0."
Chen Zhou frowned slightly as he looked at the written range.
He saw from the literature that when R = 0.97 ~ 1.0, this method can produce transparent optical grade diamond films.
Chen Zhou habitually tapped the draft paper with a pen, temporarily skipped the message, and continued reading the literature.
[The advantages of this method are simple equipment, low cost, ability to synthesize diamond in the atmosphere, fast growth rate (60-150um/h), and conducive to the deposition of diamond on large-area and complex-shaped sample surfaces.]
[The disadvantages are that the deposited diamond film has an uneven microstructure and often contains impurities such as non-diamond carbon. Due to the thermal gradient of the flame, the substrate is easily bent and deformed, and large thermal stress is generated in the film.]
"This is a method with obvious advantages and disadvantages," commented Chen Zhou.
