The indirect allowed optical transitions in (Ga0.3In0.7)2Se3

Abstract

Investigations of the absorption edge in single crystals of the (Ga0.3In0.7)2Se3 compound (hexagonal γ1-phase) are performed for two basic polarizations E ∥ c and E ⟂ c, at temperatures T = 77, 120, 180, 240, and 300 K. Anisotropy in forbidden energy gap width and its linear dependence on temperature are found. Detailed analysis of indirect allowed optical transitions for absorption coefficients within the range from 17 to 200 cm−1 is done. Selection of the central segment on the absorption curves is justified by comparison of the theoretical and experimental data.