The effects of elastic strain induced by lattice mismatch on the effective mass and band offset at Γ point are studied in this article. We found that the effective masses (electron, light- and heavy-hole) become anisotropic in a strained layer. The theoretical calculations were made using a method of linear combination of atomic orbitals, and the overlapping integrals are adjusted in accordance with the change of atomic distance. In the kz direction, the effective mass ratios (strain: unstrain) of the electron of In xGa1-xSb/GaSb structure were found to vary from 1 to 3.38 for 0≤x≤1, the corresponding ratios of the light- and heavy-hole are 1 to 3.38 and 1 to 0.99, respectively. In the kx and ky direction, the ratios of the light- and heavy-hole are 1 to 1.02 and 1 to 1.13, respectively. For unstrained and strained interfaces, the band offset ratios of 90:10 and 57:43 (conduction band: valence band) are obtained, respectively. Experimental studies were also performed on the InxGa 1-xSb/GaSb strained-layer superlattice sample. It was found that the theoretical calculations agree well with experimental results in this study.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)