The Optical Properties of Silicon Ditelluride

The optical properties of SiTe2 have been studied in the region 2.5 to 0.5 μm and in the temperature range 300 to 100°K. In the absorption spectrum three distinct regions have been observed which have been attributed to Te vacancies, indirect, and direct transitions, respectively. The fine structure in the vicinity of the indirect transitions indicates the participation of four phonons and a two‐dimensional exciton. The absorption in the vicinity of the direct transitions follows Urbach's rule. The main parameters characterising the indirect and direct transitions are determined.