Independent Design and Temperature Control Performance Experiment of the CdZnTe Crystal Growth Furnace

In response to the demand for the growth of 4-inch diameter single-crystal CdZnTe materials and based on the results obtained from studying the growth of foreign CdZnTe crystal materials, a CdZnTe crystal growth furnace based on the mobile heating method was independently designed. The heating unit of the furnace body comprises four specifications with six temperature controlled sections, which are controlled by an industrial computer that controls the servo motor to drive the ball screw linear guide to achieve lifting. The inner cavity of the furnace was fitted with a heating tube comprising corundum ceramic tubes and high-temperature metal heat pipes using high-precision platinum-rhodium-platinum thermocouples, Eurofins, transformers, and thyristor control heating units. This furnace is based on a fuzzy + PID control algorithm with a strategy to adjust and control the temperature distribution of the heating furnace. This furnace was used to perform stability and control performance experiments during temperature heating. Experimental results showed that the heating temperature of the inner cavity of the furnace was continuously controlled for 200 h, temperature fluctuation at the same position was ±0.005℃, and heating temperature deviation was ≤ ±0.1℃. The lengths of the upper and lower constant-temperature zones of the furnace cavity were 400 and 240 mm, respectively. The length of the temperature gradient zone in the middle of the furnace cavity was approximately 136 mm. The length of the constant-temperature zone in the lower part of the furnace cavity was 240 mm. At a heating temperature of approximately 1098℃, the temperature gradient was 0.92℃⋅mm⁻¹. Experimental results showed that this furnace meets the independent design and temperature control performance requirements for a CdZnTe crystal growth furnace.