Growth and Characterization of InAs_xSb_1−x Bulk Crystals and Growth Rate Measurements

Abstract

InAs _x Sb_1−x is an important material to fabricate detectors in the mid wavelength and long wavelength infrared region. The wavelength and the lattice constant for InAs _x Sb_1−x can be tuned in the range of 6.8 µ m–3.5 µ m and 6.478–6.058Å by adjusting the arsenic composition. InAs _x Sb_1−x crystals were grown by the vertical rotational Bridgman technique using GaAs (001) single crystal seed. Growth parameters such as temperature, period, ampoule design modification and cooling rate were analysed and used. A cooling rate of 0.25°C/hr is employed and the temperature of the growth region is carefully selected by suitably varying the temperature program/profile. Thermal pulse striations have been introduced inside the crystal during growth and etching technique was used to determine the real growth rate of the crystal. The chemical homogeneity and infrared transmittance analysis were carried out on the grown crystals.

Keywords:

• Bandgap
• Electron probe micro-analysis
• Etching
• Infrared transmission analysis
• InAs _x Sb_1−x
• Melt growth
• Seeded melt growth
• Striations
• Te impurity
• III-V ternary semiconductor
• Thermal pulse technique
• Vertical Bridgman technique
• XRD