Optical properties of SiAs single crystals

Abstract

Single crystals of silicon arsenide have been grown by the Bridgman technique. SiAs was found to have an optical energy gap of 2.18±0.05 eV at room temperature and seemed to exhibit a direct optical transition. The temperature coefficient of the energy gap was about −(2.8±0.5)×10−4 eV/K. From the multiple interference fringes of some SiAs samples, the refractive index was calculated. Over a wavelength equal to infinity, it had a value of 3.1±0.1, thus leading to a value of 9.6±0.6 for the high-frequency dielectric constant. The extinction coefficient near the absorption edge has also been deduced.