Temperature Dependence of the Band Gap and Exciton Photoreflectance in Layered Gallium Telluride.

Among Group III-A metal monochalcogenides, gallium telluride (GaTe) is one of the less studied materials in terms of applications and optical characterization. For the temperature dependence of the energy transitions in GaTe, photoluminescence (PL) spectroscopy is commonly used, and photomodulated reflectance (PR) is yet to be reported. In this work, layered monoclinic GaTe single crystals were synthesized by the Bridgman technique and used for the investigation of the conduction band (CB) edge and free-exciton (FX) state transitions using PR spectroscopy.