Band gap energy and valence band splitting of p-CdIn2Te4 crystal by photocurrent spectroscopy

Abstract

Single crystals of p-CdIn2Te4 were grown by the Bridgman method without a seed crystal. From photocurrent measurements, it was found that three peaks, A, B, and C, correspond to the intrinsic transition from the valence band states of Γ7(A), Γ6(B), and Γ7(C) to the conduction band state of Γ6, respectively. The crystal field splitting and the spin orbit splitting were found to be 0.2360 and 0.1119 eV, respectively. The temperature dependence of the CdIn2Te4 band gap energy was given by Eg(T)=Eg(0)−(9.43×10−3)T2/(2676+T). The Eg(0) was calculated to be 1.4750, 1.7110, and 1.8229 eV at the valence band states of Γ7(A), Γ6(B), and Γ7(C), respectively. The band gap energy of p-CdIn2Te4 at room temperature was determined to be 1.2023 eV.