Effect of Cu doping on hole mobility in CdTe

High quality CdTe thin films grown by laser deposition technique and heavily doped with Cu have recently been reported to have resistivity and hole mobility comparable to those of bulk single crystals. To explain the experimental results we have calculated the effect of Cu on the band structure and phonon spectrum of CdTe using the density functional theory (DFT) and the linearized augmented plane wave (LAPW) method. We found that the introduction of a high density of Cu can lead to a reduction in the hole-LO phonon scattering. In addition, Cu doping can remove Cd vacancies in CdTe and thereby enhance the hole mobility in CdTe.