Towards intermediate-band solar cells with InAs/AlAsSb quantum dots

The effects of GaAs_1-xSb_x thin cladding layers on the structural and optical properties of InAs self-assembled quantum dots (SAQDs) embedded in AlAs_0.56Sb_0.44 barriers were investigated. A cladding layer configuration of a layer of GaAs beneath the SAQDs, and a GaAs_0.95Sb_0.05 capping layer above improves SAQD morphology and enhances photoluminescence intensity. Power-dependent and time-resolved photoluminescence were used to confirm the existence of type-II band alignment. The properties shown by this quantum dot system have great potential for intermediate band solar cell applications.