Theoretical study of Si in ZnO

ORAL

Abstract

Recently, the presence of silicon in relatively high concentrations has been detected in samples of ZnO [1]. The properties of this impurity have not yet been investigated. Here we present a first-principles study of the electronic and structural properties of Si in zinc-blende ZnO using density functional calculations with LDA, GGA, and hybrid functionals. Our calculations show that substitutional Si on a Zn site is lower in energy than either Si on an oxygen site or a Si interstitial. The calculations consistently predict Si to be a shallow donor in ZnO, with the 2+ charge state being most stable across the band gap. The formation energy of substitutional Si is relatively low, supporting experimental evidence which shows a concentration of 10$^{17}$ cm$^{-3}$ Si in ZnO samples. The properties of Ge in ZnO are also studied for comparison and show behavior similar to that of Si. [1] M.D. McCluskey and S.J. Jokela, Physica B \textbf{401-402}, 355 (2007).

–

Authors

  • John Lyons

    Materials Department, University of California, Santa Barbara, CA 93106-5050

  • Anderson Janotti

    Materials Department, University of California, Santa Barbara, University of California, Santa Barbara, Materials Department, University of California at Santa Barbara, Materials Department, University of California, Santa Barbara, CA 93106-5050, University of California - Santa Barbara

  • Chris Van de Walle

    Materials Department, University of California, Santa Barbara, CA 93106-5050, Materials Department, University of California, Santa Barbara, University of California, Santa Barbara, Materials Department, University of California Santa Barbara, UCSB, Chris Van de Walle, University of California, Santa Barbara, Materials Department, University of California at Santa Barbara