Temperature dependence of photocurrent and optical band gap in CdIn2Te4 single crystals

Abstract

Single crystals of p-CdIn2Te4 were grown by the Bridgman method without using seed crystals. From photocurrent measurements, it was found that three peaks, A, B, and C, correspond to the intrinsic transition from the valence band states of Γ 7(A), Γ 6(B), and Γ 7(C) to the conduction band state of Γ 6, respectively. Crystal field splitting and spin orbit splitting were found to be at 0.2360 and 0.1119 eV, respectively, from found to be photocurrent spectroscopy. The temperature dependence of the CdIn2Te4 band gap energy was given by the equation Eg(T) = Eg(0) − (9.43 × 10−3)T2/(2676 + T). Eg(0) was estimated to be 1.4750, 1.7110, and 1.8229 eV at the valence band states of A, B, and C, respectively. The band gap energy of p-CdIn2Te4 at room temperature was determined to be 1.2023 eV.