Molecular beam epitaxy growth and characterization of GaSb / AlSb strained-layer superlattices on nonvicinal (001) and 111 (B) GaSb substrates

Abstract A comparison of the MBE growth of GaSb/AlSb strained-layer structures has been carried out for (001) and (111)B GaSb substrates. Optimal in vacuo cleaning procedures were found to differ and are delineated. The growth rate for (111)B is 10% larger than (001) for the same beam fluxes and substrate temperature. Growth on the (001) orientation is specular, whereas growth on nonvicinal (111)B is faceted. Varying the substrate temperature and V/III flux ratio did not result in specular growth on the (111)B orientation. Strong excitonic luminescence is observed for single and multiple quantum well structure grown on both substrate orientations. Systematic excitonic peak shifts are observed from strained and unstrained GaSb wells by changing the buffer layer which separates the substrate and superlattice. The degree of strain retained in the GaSb wells has been examined from analysis of the optical mode frequency shifts measured by Raman scattering.