Dependence of the microstructural and the electrical properties on the annealing temperature and Hg-cell fluxes for in situ annealed Hg 0.7Cd 0.3Te epilayers grown on CdTe buffer layers

Abstract

Scanning electron microscopy images showed that the surface morphologies of in situ annealed Hg 0.7Cd 0.3Te epilayers grown on CdTe buffer layers by using molecular beam epitaxy were mirror-like with no indication of pinholes. Selected area electron diffraction patterns and high-resolution transmission electron microscopy images of the as-grown and the in situ annealed Hg 0.7Cd 0.3Te epilayers showed that the microstructural properties of the Hg 0.7Cd 0.3Te epilayers were improved by annealing. Hall-effect measurements showed that n-Hg 0.7Cd 0.3Te epilayers were converted to p-Hg 0.7Cd 0.3Te epilayers by in situ annealing and that the carrier concentration and the mobility of the Hg 0.7Cd 0.3Te epilayers were dramatically changed by varying the annealing temperature and Hg-cell fluxes. These results indicate that the microstructural and the electrical properties of Hg 1− x Cd x Te epilayers can be significantly affected by the in situ annealing conditions.