Anisotropy of the Optical Band Edge Absorption in CuInTe 2 Single Crystals

Optical absorption of p‐CuInTe 2 (I 4 2d) single crystals is studied near the band edge in linearly polarized light in the temperature range 370 to 77 K. Band edge absorption in E ∥︁ c and E ⟂ c polarizations follows Urbach's rule and is described by an electron‐phonon mechanism. The minimal optical transitions in CuInTe 2 are allowed primarily in E ⟂ c polarization and correspond to a band gap of 0.983, 0.994, and 1.038 eV for T = 370, 300, and 77 K, respectively. The single crystals reveal optical linear dichroism near the band edge reaching an amplitude T ≈ 70%. The optical anisotropy correlates with the deformation of the chalcopyrite lattice, the transmission in linearly polarized light obeying the generalized Malus law. The CuInVI 2 (VI = S, Se, Te) crystals are found to have a temperature coefficient of band gap width substantially smaller than that typical of their binary analogs, the II‐VI compounds. [Russian Text Ignore].