Influence of boron doping on the photosensitivity of cubic silicon carbide

Abstract

Photoelectric properties have been studied for 3С-SiC single crystals obtained by thermal decomposition of methyl trichlorosilane with addition of boron in the process of growing or using diffusion into intentionally undoped crystals. Boron-doped samples demonstrate the band of photosensitivity within the range 1.3...2.0 eV with the peak near 1.7 eV. Doping of 3С-SiC single crystals with B impurity leads to appearance of an efficient recombination center with the thermal activation energy 0.27 ± 0.02 eV inside the band gap and to widening the spectral sensitivity of the material over the impurity longwave range. Availability of boron results in changing the temperature dependence of photoconductivity from the decay characteristic to the activation one. It will allow expanding the operation range of devices based on 3C-SiC〈B〉 up to 500 °С and above it. In addition, the lux-ampere characteristics becomes linear, i.e., more convenient from the metrological viewpoint. Depending on the type of doping of 3C-SiC〈B〉 samples, pronounced variations of line positions in photoluminescence spectra in near-infrared range are revealed.