Method and equipment for growing monocrystal of cadmium selenide by gas-phase vertical pulling

Abstract

A vertical gas-phase pulling-up method for growing cadmium selenide monocrystal features that the cadmium selenide powder is used as raw material and the purification of raw material and the growth of monocrystal are performed in a single ampoul consisting of tubular body divided into purifying and growing segment, heat conducting rod and hanging ring. The said method includes cleaning ampoul, charging raw material, vacuumizing, sealing, multi-stage purifying, cutting and separating ampoul, thermal cleaning growing segment, growing crystal and cooling. The resultant monocrystal features complete structure, high uniformity, low stress, bit size phi(10-20)X(30-40)mm and high resistivity (10 to power 6-8 omega cm).

Description

1. Technical field [0001] The invention belongs to the field of single crystal preparation, in particular to a method for growing cadmium selenide single crystal. 2. Background technology [0002] Cadmium selenide (CdSe) single crystal is a II-VI wide bandgap compound semiconductor material. In recent years, it has attracted much attention due to its excellent room temperature nuclear radiation detection performance and nonlinear optical performance. High (1239°C), the vapor pressure of the two components that make up it is relatively large, and the thermal conductivity of the crystal is low, so it is difficult to prepare large-sized high-quality cadmium selenide single crystals. At present, the preparation of CdSe single crystal mainly adopts liquid phase method, temperature gradient melt zone melting method and static vapor phase growth method. The disadvantage of the liquid phase method is that the size of the grown single crystal is small, generally several millimeters,...

AI Technical Summary

Problems solved by technology

The disadvantage of the liquid phase method is that the size of the grown single crystal is small, generally a few millimeters, and the crystal contains residual solvent package, so the application is limited

The disadvantages of the temperature gradient melt zone melting method are: 1. Crystal growth requires a high-pressure vessel, resulting in increased cost and increased insecurity; 2. The grown crystal has high stress, many defects, and low quality

The shortcomings of the static vapor phase growth method are: 1. The crystal grows statically, causing the crystallization interface to move, the growth temperature gradient is not constant, and the radial temperature field is unevenly distributed, thus affecting crystal growth and making it difficult to form a single crystal with complete and uniform structure; 2. The grown crystal resistivity is low, generally in the range of 10 1～2 Ωcm

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