The effect of the maximum furnace temperature on the crystallization quality and photoelectric properties of GaInSb crystals grown with the traveling heater method

Abstract

Ga_1−xIn_xSb (0 < x < 1) single crystals can be used as the substrates to epitaxially grow a variety of components required for high-performance infrared detectors and lasers. Ga_0.92In_0.08Sb crystals (25 mm diameter, 120 mm length) were prepared with both the vertical Bridgman (VB) and the traveling heater method (THM). The effects of the maximum furnace temperature on the structures and photoelectric properties of GaInSb crystal were investigated. Compared with the VB, the THM reduced the In element segregation and dislocation density of the GaInSb crystal, and improved its photoelectric properties. Moreover, the crystallization quality of GaInSb crystal improved with the decrease of the maximum furnace temperature of the THM. The axial segregation of In element in the GaInSb crystals decreased from 0.110 mol%/mm to 0.081 mol%/mm, while the radial segregation increased from 0.057 mol%/mm to 0.089 mol%/mm. And the dislocation density reduced from 3.295 × 10³ cm⁻² to 2.604 × 10³ cm⁻². The carrier concentration increased from 1.254 × 10¹⁸ cm⁻³ to 1.463 × 10¹⁸ cm⁻³, the carrier mobility increased from 1422 cm²/(V·s) to 1676 cm²/(V·s), and the resistivity reduced from 1.617 × 10^–3 Ω cm to 1.393 × 10^– Ω cm. And the infrared transmittance of GaInSb crystal improved from 43 to 47%.