Feasibility study of cadmium zinc telluride growth using a submerged heater in a vertical bridgman system

Abstract

Computer simulations are performed to assess the feasibility of a submerged heater system for growth of cadmium zinc telluride (CZT). Adding a submerged heater to the vertical Bridgman configuration in the manner of the submerged heater method (SHM) and axial-heat-flux-close-to-the-phase-interface (AHP) systems allows superior control of the growth interface shape and significant reduction in thermal stress. Simulations demonstrate that maintaining a constant gap width between heater and growth interface is critical to achieving uniform axial segregation when using zone leveling. Radial segregation remains somewhat nonuniform, however, because of the poor mixing in the interface region.

Interface Shape under the Insulating Baffle in Vertical Bridgman Systems

“…The simulations were conducted using CdTe properties, because CdTe and CZT are particularly difficult to grow, in part due to their low thermal conductivity ( λ CZT ≈ 1 W m‐K −1 ). [ 12,26 ] Thus, in the VB configuration without a baffle, the s/l interface of CZT is usually concave. [ 26 ]…”

“…Numerous further papers discussed this approach. [6,[11][12][13][14] The former approach involves also VB growth techniques with permanent magnetic fields, [15,16] while the latter includes rotating/oscillating/vibrating baffle/ampoule [10,11,17,18] and magnetic stirring by unsteady rotating [19] and traveling magnetic fields. [20] The vibrational techniques are well known as accelerated crucible rotation technique, the angular vibration technique, the coupled vibrational stirring of the ampoule, and ultrasonic vibrations.…”

Heat Transfer Analysis and Design for Bulk Crystal Growth: Perspectives on the Bridgman Method

“…Our initial studies focused on infrared detector material grown by both vertical [59,[126][127][128][129][130] and horizontal [131][132][133] Bridgman techniques. Yeckel and Derby [137,138] studied the influences of transient flows driven by the accelerated crucible rotation technique (ACRT) on zinc segregation; in [139], they considered the effects of a submerged heater on shaping the interface during CZT growth. Yeckel and Derby [137,138] studied the influences of transient flows driven by the accelerated crucible rotation technique (ACRT) on zinc segregation; in [139], they considered the effects of a submerged heater on shaping the interface during CZT growth.…”

Modeling and bulk crystal growth processes: What is to be learned?

“…The end result is that typical yields of useable material from a crystalline boule remain at 10% or lower, resulting in very high materials costs. Our modeling efforts have been directed to better understand the difficulties of CZT growth and suggest improvements [66][67][68][69][70][71][72][73][74][75][76][77][78].…”