Optical Band Edge Absorption in CuInSe₂

Abstract

Abstract Optical properties are studied of (100) oriented CuInSe 2 (D ) crystals near the absorption edge. While the edge absorption spectra in the range 80 to 370 K are found to follow Urbach's rule, there are two regions in α(ħω) differing in the temperature dependence of Urbach's parameter. The results obtained suggest that the optical band edge absorption in CuInSe 2 is dominated by electron–phonon interaction. Linear optical dichroism of the edge absorption in chalcopyrite‐structure CuInSe 2 is revealed and investigated. CuInSe 2 is established to differ from the other chalcopyrite crystals in a negative linear dichroism near the absorption edge.