Method for preparing indium phosphide crystal by utilizing indium-phosphorus mixture

A method for preparing an indium phosphide crystal by using an indium-phosphorus mixture, characterized by comprising following steps of:

• 1) preparing an indium-phosphorus mixed ball:
• uniformly mixing indium powder and red phosphorus powder according to a designed mass ratio, and pressing into a spherical shape;
• 2) charging:
• putting the indium-phosphorus mixed ball mixed boron oxide powder into a feeder in a furnace body, and putting a boron oxide block into a crucible;
• 3) keeping high furnace pressure and low temperature of the indium-phosphorus mixed ball:
• keeping the low temperature of the indium-phosphorus mixed ball in the process of feeding the indium-phosphorus mixed ball from the feeder to the crucible, preventing indium or phosphorus from melting and gasifying, and keeping the pressure in the furnace greater than the dissociation pressure of indium phosphide;
• 4) melting covering agent:
• heating the crucible, melting the boron oxide block, and covering the bottom of the crucible with a boron oxide liquid;
• 5) feeding, synthesizing and crystal growing:
• feeding the mixture of the indium-phosphorus mixed ball and the boron oxide powder into a crucible below the liquid level of the boron oxide, simultaneously controlling the temperature of the crucible to enable the indium-phosphorus to react to synthesize indium phosphide, adjusting the temperature after the melt amount of the indium phosphide reaching a set amount, and carrying out crystal growth by adopting a high-pressure liquid encapsulation pulling method.