Coexistence of Type-I and Type-II Band Alignment in Ga(Sb, P)/GaP Heterostructures with Pseudomorphic Self-Assembled Quantum Dots?

摘要

Band alignment of heterostructures with pseudomorphic GaSb_(1 – x)P_x/GaP self-assembled quantum dots (SAQDs) lying on a wetting layer was studied. Coexistence of type-I and type-II band alignment was found within the same heterostructure. Wetting layer has band alignment of type-I with the lowest electronic state belonging to the X_(XY) valley of GaSb_(1 – x)P_x conduction band, in contrast to SAQDs, which have band alignment of type-II, independently of the ternary alloy composition x. It is shown that type-I–type-II transition is a result of GaP matrix deformation around the SAQD.