A photoluminescence and Hall-effect study of GaSb grown by molecular-beam epitaxy

Publisher Website
Google Scholar
Abstract
Unintentionally doped gallium antimonide has been grown by molecular‐beam epitaxy on gallium arsenide and gallium antimonide. Substrate temperatures in the range 480 to 620 °C and antimony to gallium flux ratios from 0.65 : 1 to 6.5 : 1 have been investigated. The deposition conditions have been related to growth morphology and to the electrical and optical properties of the epitaxial films. A strong correlation has been found between the quality of the layers and the degree of excess antimony flux; the best material in terms of both optical and electrical properties was obtained with the minimum antimony stable growth at a particular substrate temperature. All the material exhibited residual p‐type behavior. The lowest hole concentration achieved was 7.8×1015 cm−3 with a corresponding room‐temperature mobility of 950 cm2/V s. The narrowest PL (photoluminescence) features observed were peaks associated with bound exciton transitions with half‐widths of 2–3 meV.