OPTICAL-ABSORPTION NEAR THE FUNDAMENTAL ABSORPTION-EDGE IN GASB

The fundamental absorption of GaSb, experimentally investigated by opt ical transmission measurements performed in the temperature range 9-30 0 K on nominally undoped molecular-beam-epitaxy-grown GaSb layers, is compared to theory. Calculations related to a band-to-band optical tra nsition theory based on the models of Kane and Elliott, considering th e band nonparabolicity and the electron-hole (exciton) interaction eff ects, respectively, show excellent agreement with experimental results . The role of different contributions to absorption coefficient is dis cussed.