Crystal Growth and Properties of Boron Monoarsenide

Boron arsenide, a semiconductor with an energy gap of 1.46 eV, decomposes irreversibly at temperatures above 900 °C, thus limiting the temperature of the crystal growth process. In this work, single crystals of boron arsenide, identified by the x-ray diffraction method, have been prepared by the chemical transport of polycrystalline boron arsenide in the presence of a temperature gradient. The transported crystals are p type and have a resistivity of approximately 0.01 Ω cm in the temperature range 77–500 °K. The hole concentration and Hall mobility, essentially independent of temperature in the range 77–300 °K, have been estimated to be in the ranges of 1018–1019 cm−3 and 100–400 cm2V−1sec−1, respectively. In spite of the high carrier concentrations, the transported crystals are suitable as substrates for the epitaxial growth of boron arsenide with controlled dopant distribution.