2000 character limit reached
First-principles DFT + GW study of the Te antisite in CdTe (1607.06193v1)
Published 21 Jul 2016 in cond-mat.mtrl-sci and cond-mat.other
Abstract: Formation energies, charge transitions levels, and quasiparticle defect states of the tellurium antisite $(\text{Te}\text{Cd})$ in CdTe are addressed within the DFT${0.05cm}+{0.05cm}$\emph{GW} formalism. We find that $(\text{Te}\text{Cd})$ induces a (+2/0) deep level at 0.99 eV above the valence band maximum, exhibiting a negative-U effect. Moreover, the calculated zero-phonon line for the excited state of $(\text{Te}_\text{Cd})0$ corresponds closely with the $\sim$1.1 eV band, visible in luminescence and absorption experiments. Our results differ from previous theoretical studies, mainly due to the well-known band gap error and the incorrect position of the band edges predicted by standard DFT calculations.