Controlled optical properties of GaSb/InGaAs type-II quantum dots grown on InP substrate

Effect of GaSb/InGaAs quantum dots (QDs) morphology and In composition in InGaAs interlayer on the optical properties of GaSb/InGaAs QD material system was studied in this work. The interband transition of GaSb QD and type-II transition from the InGaAs conduction band to the GaSb hole level were observed. It was found that both QD morphology and In composition in InGaAs interlayer had an influence on the optical properties of GaSb/InGaAs QD material system. Note that the linear relationship exists between In composition in InGaAs interlayer and photoluminescence peak positions, which indicates the structural characteristics of the InGaAs matrix can be used as an important tool to adjust the optical properties of GaSb/InGaAs QD material system. This experimental result shows that the optical properties of GaSb/InGaAs type-II QD material system can be more precisely controlled than the widely studied GaSb/GaAs QD material system. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729939]