Indium nitride (InN) is a kind of nitride semiconductor material. Its stable phase under normal temperature and pressure is hexagonal wurtzite structure, which is a direct band gap semiconductor material.
Indium nitride has good steady-state and transient electrical transmission characteristics. It has a large electron mobility, a large peak rate, a large saturated electron drift rate, a large peak rate, and a small band gap. The excellent properties such as smaller effective electronic mass make indium nitride more suitable for the preparation of high-frequency devices. It has unique advantages in the development of high-frequency, high-rate transistor applications, especially in the preparation of terahertz devices, chemical sensors, Semiconductor light-emitting diodes, full-spectrum solar cells and other photoelectric devices have huge application value.
However, preparing indium nitride materials is not easy.
Innovation
Recently, scientists at Linkping University in Sweden have developed a new molecule that can be used to prepare high-quality indium nitride, making it possible to use indium nitride in high-frequency electronic devices and other products. The research results were published in the journal "Chemistry of Materials".
Technology At present, the bandwidth we use for wireless data transmission will soon be exhausted. If we want to continue to increase the amount of data transmitted, we must increase the available bandwidth by using more frequencies (terahertz). Indium nitride may become part of this solution. The leader of the study, Henrik Pedersen, a professor of inorganic chemistry at Linköping University’s Department of Physics, said: “Electronics pass through indium nitride very easily, so they can move forward or backward through this material at a very high speed. It then sends electrons and generates signals at very high frequencies. This means that indium nitride can be used in high-frequency electronic devices, such as in these electronic devices, to provide new frequencies for transmitting wireless data." Indium nitride consists of nitrogen and a A variety of metal elements indium. It is a semiconductor that can be applied to transistors, and transistors are the basis of all electronic devices. The problem is that the indium nitride film is difficult to prepare. Thin films similar to semiconductor materials are usually prepared by a mature method, also known as "chemical vapor deposition (CVD)". This method uses temperatures between 800 degrees Celsius and 1000 degrees Celsius. However, when the temperature rises above 600 degrees Celsius, indium nitride will decompose into its components indium and nitrogen. In this study, the scientists used a variant of CVD technology, the so-called "atomic layer deposition (ALD)", which uses a lower temperature.
They developed a new molecule called "triazene-indium complex (indium triazenide)". No one has studied this triazene-indium complex before, but researchers at Linköping University soon discovered that triazene molecules are an excellent starting material for making thin films.
Compared with those previously studied, the molecules studied here occupy the position before the carbon atom with a nitrogen atom. This places the indium atom in the center of the molecule, surrounded by three molecular fragments, where the three nitrogen atoms form a "bridge" (triazene). (Image source: Karl Rnnby)
Most materials used in electronic devices must be produced by making thin films on the surface that controls the crystal structure of electronic materials. This process is called "epitaxial growth". The researchers found that if silicon carbide is used as a substrate, it is possible to achieve epitaxial growth of indium nitride, which was previously unknown. In addition, the indium nitride prepared by this method is extremely pure and is one of the best indium nitrides in the world.
Henrik Peterson said: "The molecule we prepared (triazene-indium complex) makes it possible to use indium nitride in electronic devices. We have shown that we can guarantee that indium nitride is pure enough to be used by Describe it as a way of making genuine electronic materials."
The researchers described another surprising fact. Those who use ALD generally believe that molecules should not be allowed to react or decompose in any way in the gas phase. However, when the researchers changed the temperature of the coating process, they found that the temperature at which the process was stable was not one, but two. Henrik Peterson said: "The triazene-indium complex is decomposed into smaller fragments in the gas phase, which improves the ALD process. This is a paradigm shift in the ALD category, which means that it is not completely stable in the gas phase. Molecule. We prove that if we allow new molecules to decompose to a certain extent in the gas phase, we will eventually get a better result." Researchers are currently testing similar complexes of triazene with other metals instead of indium, and The use of them in the ALD process to produce molecules yielded promising results.