Coexistence of type-I and type-II band alignment in Ga(Sb,P)/GaP heterostructures with pseudomorphic self-assembled quantum dots

Band alignment of heterostructures with pseudomorphic GaSb$_{1-x}$P$_{x}$/GaP self-assembled quantum dots (SAQDs) lying on 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.