Ab initioStudies of Electronic Structure of Defects in PbTe

Abstract

AbstractAb initioelectronics structure calculations have been carried out in a series of RPb2n-1Te2n, n=16, compounds to understand the nature of “defect” states introduced by R where R = vacancy, monovalent Na, K, Rb, Cs, Ag atoms and divalent Cd atoms. We find that the density of states (DOS) near the top of the valence band and the bottom of the conduction band get significantly modified. The Na atom seems to perturb this region least (ideal acceptor in PbTe) and the other monovalent atoms enhance the DOS near the top of the valence band. Cd is an interesting case, since it introduces a strong resonance state near the bottom of the conduction band.