Defect Structure Rebuilding by Ion Beam Milling of As and Sb Doped p-Hg1–xCdxTe

Abstract

This study focuses on developing an understanding of the mechanisms of ion beam milling induced p-to-n conversion in extrinsically (As or Sb) doped p-Hg1––xCdxTe with x 0.2. The basis of modeling is the quasichemical approach and the model of superfast Hg interstitial atoms diffusion that has permitted to explain the similar conversion occurred in Hg vacancy-doped p-type Hg1––xCdxTe. In an acceptor doped material a donor is generated due to the formation of a complex (of interstitial Hg atom and an As or Sb atom located in the Te site). This model provides reasonably good fits with the experimental results obtained for As and Sb doped Hg1––xCdxTe epitaxial layers where the electron concentration in the converted n-layer corresponds to the concentration of the p-type dopants. Different efficiency of the conductivity conversion observed for As and Sb doped samples may be explained by different enthalpy of complex formation calculated for AsTe–HgI and SbTe– HgI pairs.