Ab initio studies of the electronic structure of defects in PbTe

Salameh Ahmad, S. D. Mahanti, Khang Hoang, M. G. Kanatzidis

Research output: Contribution to journalArticle

111 Citations (Scopus)

Abstract

Understanding the detailed electronic structure of deep defect states in narrow band-gap semiconductors has been a challenging problem. Recently, self-consistent ab initio calculations within density functional theory using supercell models have been successful in tackling this problem. In this paper, we carry out such calculations in PbTe, a well-known narrow band-gap semiconductor, for a large class of defects: cationic and anionic substitutional impurities of different valence, and cationic and anionic vacancies. For the cationic defects, we study the chemical trends in the position of defect levels by looking at series of compounds R Pb2n-1 Te2n, where R is vacancy or monovalent, divalent, or trivalent atom. Similarly, for anionic defects, we study compounds M Pb2n Te2n-1, where M is vacancy, S, Se or I. We find that the density of states near the top of the valence band and the bottom of the conduction band get significantly modified for most of these defects. This suggests that the transport properties of PbTe in the presence of impurities may not always be interpreted by simple carrier doping (from bound impurity states in the gap) concepts, confirming such ideas developed from qualitative and semiquantitative arguments.

Original languageEnglish
Article number155205
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume74
Issue number15
DOIs
Publication statusPublished - Oct 26 2006

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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