A method for preparing gallium nitride nanocrystals using a twin-screw extruder

Abstract

The invention belongs to the field of inorganic compound semiconductor materials, in particular to a method for preparing gallium nitride nanocrystals by using a twin-screw extruder. Firstly, the metal gallium salt is dissolved in the water-soluble polymer aqueous solution to form a slurry, and the slurry is pumped into the twin-screw extruder, and the slurry passes through the dispersing screw element, so that the gallium salt is coated on the hydrogel network formed by the water-soluble polymer In the structure, the water-soluble polymer is carbonized under shear and high temperature conditions to form a gallium salt covered by a carbon network structure; thermoplastic glue is added through the auxiliary material port, and the mixing reaction is extruded to form a thin sheet; the thin sheet is placed in a tubular After drying in the furnace, raise the temperature of the tube furnace to 900-1200°C, pass through the ammonia gas for 120-150 minutes, stop the flow of ammonia gas and cool to room temperature in an argon atmosphere to obtain a light yellow nitride with regular crystal form. gallium nanocrystals. The gallium nitride crystal prepared by the invention has good surface appearance, regular crystal form, high yield and high purity, and has wide application value.

Description

technical field [0001] The invention belongs to the field of inorganic compound semiconductor materials, in particular to a method for preparing gallium nitride nanocrystals by using a twin-screw extruder. Background technique [0002] Gallium nitride, together with semiconductor materials such as silicon carbide (SiC) and diamond, is known as the third-generation semiconductor material. Compared with traditional silicon-based and gallium arsenide-based semiconductor materials, third-generation semiconductor materials such as gallium nitride are due to their The unique band gap range, excellent optical and electrical properties and excellent material properties can meet the working requirements of high-power, high-temperature, high-frequency and high-speed semiconductor devices, and have a wide range of applications in the automotive and aviation industries, medical, military and general lighting application prospects. [0003] GaN material is a direct transition wide bandg...

AI Technical Summary

Problems solved by technology

[0005] Added to concentrated nitric acid and heated by microwave hydrothermal heating to form GaO 2 H nanorods, then the GaO 2 The H nanorod powder is placed in a tube furnace and reacted with ammonia gas at high temperature to obtain light yellow GaN nanocrystals. The advantages are that the raw materials are relatively cheap and the process operation is simple. However, due to the need to use concentrated nitric acid in the preparation process, the safety factor is low. Moreover, the precursor nanorods are not conducive to the growth of gallium nitride crystals, and it is not easy to obtain high-quality gallium nitride crystals

[0006] Chinese Patent Publication No. CN1944268 discloses a method for preparing gallium nitride nanocrystals by a sol-gel method. First, a gallium oxide / amorphous carbon mixture is prepared by a sol-gel method, that is, gallium nitrate is dissolved in concentrated nitric acid, and citric acid is added. After heating and stirring for 2 hours, it becomes a transparent gel after cooling, put it into a ceramic tube after drying, and react with ammonia gas at a temperature of 850-950°C to obtain light yellow GaN nanocrystals. This method can produce a large number of particle diameters smaller than or equal to Bohr excitons However, due to the need to use concentrated nitric acid in the preparation process, the safety factor is low, and the area of ​​the prepared nanocrystals is small, which affects the performance of gallium nitride crystals and is not conducive to large-scale production

[0007] However, in the above-mentioned method, due to the low crystal growth rate, long period, and the irregular shape of the generated crystals, the quality of gallium nitride nanocrystals is affected, and it is not easy to popularize the large-scale industrial production of gallium nitride nanocrystals. Therefore, it is necessary to find a simple , fast and low-cost preparation of high-quality GaN nanocrystals has become the unremitting goal of researchers in the field of optoelectronic materials