Spontaneous emission from InAs/GaSb quantum wells grown by molecular beam epitaxy

We have investigated the spontaneous emission from InAs/GaSb quantum wells grown by molecular beam epitaxy. A strong photoluminescence signal was obse rved only from samples grown in a narrow substrate temperature range around 400 degrees C with InSb-like interfaces. From an analysis of the photolumi nescence energy with the excitation density, we demonstrated the formation of triangular quantum wells for holes in the GaSb barriers close to the int erfaces. Finally, the temperature dependence of the photoluminescence peak energy showed a deviation from the InAs band gap evolution at low temperatu re, which could be related to the type II broken gap band alignment. (C) 19 99 American Institute of Physics. [S0021-8979(99)03203-X].