Electronic structure calculations of delafossite Cu-based transparent conducting oxidesCuMO2(M=B,Al,Ga,In)by quasiparticle self-consistentGWapproximation and Tran-Blaha's modified Becke-Johnson exchange potential

Abstract

In this work, band gaps of the delafossite Cu-based transparent conducting oxides $\mathrm{Cu}M{\mathrm{O}}_{2}$ $(M=\mathrm{B},\mathrm{Al},\mathrm{Ga},\mathrm{In})$ are calculated by density functional theory (DFT) implemented with many-body perturbation theory (MBPT) based on quasiparticle self-consistent GW approximation (QPscGW) and with Tran-Blaha's modified Becke-Johnson functional (DFT-TB09). Their band gaps are explicitly improved from DFT within local density approximation (LDA). Their optical absorption spectra are also calculated by solving Bethe-Salpeter equation (BSE) that includes the electron-hole correlation effect; they show strong excitonic peaks.