Chapter 91 The key points of the problem
"Tungsten diselenide?"
Xu Chuan muttered it, he knew the name.
It is a typical low-dimensional transition metal chalcogenide semiconductor material, an inorganic compound with a layered structure, and has good physical, chemical and electrical properties.
Widely used in energy storage batteries, lubrication, semiconductors, photovoltaics, aerospace, aviation, military, national defense and other fields.
For example, it can be used as a positive electrode material for lithium-sulfur batteries or anode materials for lithium batteries. It can also be used to make various things such as transistors, photoelectrodes, and single-photon emitters.
At present, it is still a cutting-edge research object in the materials industry, but it will become very popular in the next ten years and be common in almost every university.
It seems that his mentor's vision is indeed very good, but he seems to have never heard of his mentor researching this aspect in his previous life. It seems that the research failed.
Otherwise, it would be impossible for no news to be conveyed.
After all, most people would talk about their past failures when they are idle, isn't it just to show off what achievements they have made?
Moreover, it is very common to fail when developing a new material. It is normal for funds to be broken, problems to be solved to be encountered, mentors to leave, and the R&D team to be poached.
After all, there are so many universities, materials research institutes, materials laboratories, and materials companies in China. Even though the field of materials is very broad, only those are valuable and popular.
Just like Chen Zhengping can see that low-dimensional materials, transition metal chalcogenide materials, are a hot prospect in the future, let alone other people who have been involved in the materials industry for many years, they can definitely see it. After all, everyone is also a veteran. .
Therefore, the competition between each other is really not small, and everyone is rushing to compete for time, or simply throw money at others.
For example, Zhejiang University has taken money from Nanjing University, and even P University and Shuimu over the years to steal many professors and laboratory personnel, and even to the extent of recruiting researchers from the other party's entire project.
It is precisely because of this that the influence of Zheda has been rising steadily over the years.
More importantly, the materials industry is really in a hurry and the winner takes all.
If you can make the materials a month or even half a month in advance, and successfully pass the patent release, then the latecomers will really lose their pants and not even be able to take a sip of soup.
"Mentor, Xu Chuan is here."
After bringing the person over, Fan Pengyue called out to Chen Zhengping who was busy.
"Teacher." Xu Chuan also greeted him.
"Well, okay, Xu Chuan, please wait a moment while I finish the experiment in my hand. Fan Pengyue, please take Xu Chuan to understand our project first."
Chen Zhengping replied without even raising his head, staring at the experimental equipment in front of him.
"Then come with me, junior brother." Fan Pengyue smiled honestly and took Xu Chuan to visit the materials laboratory. While visiting, he explained:
"The material we are studying in this project has just been mentioned, it is tungsten diselenide, which is a low-dimensional material."
"Oh, I forgot to explain what low-dimensional materials are. The so-called low-dimensional materials are materials that do not exceed the nanometer level in three dimensions. Specifically, they are two-dimensional, one-dimensional and zero-dimensional materials."
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"Zero-dimensional materials are also called quantum dots. They are composed of a few atoms or molecules stacked up. The size of the particles is on the nanometer scale. For example, atomic clusters of semiconductors and metals are typical zero-dimensional materials."
"One-dimensional materials are called quantum wires, and the thickness of the wires is on the order of nanometers. For example, carbon nanotubes and one-dimensional graphene are one-dimensional materials."
"Two-dimensional materials include the interface of two materials, or a thin film attached to a substrate. The depth of the interface or the thickness of the film layer is on the order of nanometers, such as metal nanoplates." "We are studying tungsten diselenide this time. Two-dimensional materials.”
"Well, these concepts shouldn't be difficult for you, but for now you just need to understand them. There is no need to go into depth."
"Currently, our main sticking point is how to tile tungsten diselenide in a single-atom structure on a silicon oxide silicon wafer or an optical sapphire wafer, so that it can form a nanometer-scale single-layer structure."
"But in every tiling experiment, tungsten diselenide will eventually appear."
Fan Pengyue briefly introduced the current project situation and progress, and also briefly explained the knowledge about materials.
After all, to solve material mathematics problems, it is impossible even if you don’t know the material at all.
"What do you need me to do?" Xu Chuan asked in confusion.
After listening to Fan Pengyue's explanation, he already roughly knew where the problem lay.
Tungsten diselenide is a typical sulfide low-dimensional material. Although he has not studied it, he has studied many similar materials in his previous life.
Nanomaterials were the focus of his research in his previous life.
If nothing unexpected happens, the reason why there are problems with the tiling of tungsten diselenide should be due to the eutectic effect of tungsten diselenide.
Because tungsten diselenide is an inorganic compound with a layered structure and has a hexagonal structure similar to molybdenum disulfide, each tungsten atom is bonded to six selenium atoms in a triangular prism coordination manner, and each selenium atom is It is in a pyramidal configuration with three tungsten bonds.
The bond length between tungsten and selenium is 2.526, and the bond length between selenium and selenium is 3.34, and the layers are combined by van der Waals forces.
Generally speaking, there are many methods for preparing two-dimensional nanosheet materials, such as mechanical exfoliation, liquid phase exfoliation, electrochemical exfoliation, chemical vapor deposition, hydrothermal methods, etc.
Except for the mechanical stripping method, most of these methods are suitable for tungsten diselenide.
However, due to the existence of van der Waals forces, the peeled off tungsten diselenide nanosheets are not stable and are easily stacked together again through van der Waals forces.
This is probably the main reason why this project has always been stuck.
"We need your help to analyze the data to see what hinders the complete crystallization of tungsten diselenide during the tiling process. This part is about functional analysis. I have studied it with Professor Zhou Hai before. For a while, but obviously, you know, I had almost no talent for math.”
"So I'm leaving it to you."
"Of course, I will assist you throughout the process. I will tell you the meaning of each experimental data and the corresponding experimental steps, so that it may be faster."
Fan Pengyue sighed. Neither he nor his tutor were good at functional analysis. Although his tutor knew a little more than him, he was still in a mess about these mathematics and couldn't find any ideas.
But this is normal, not everyone is as perverted as the little junior brother in front of me.
In fact, the physics department at the undergraduate level of ordinary universities does not offer functional analysis as a course at all. Even if you choose to minor, you can only go to the School of Mathematics to audit it.
Therefore, physicists in the physics world are generally not good at mathematics, except for Witten and the pervert in front of him.