Band lineup of pseudomorphic $GaAs1−xSbx$ quantum-well structures with GaAs, GaAsP, and InGaP barriers grown by metal organic chemical vapor deposition

We report the growth of thin pseudomorphic $GaAs1−xSbx$ $(x∼0.3)$ quantum-well heterostructures by metal-organic chemical vapor deposition and the measurement of the band lineups for the heterointerface of $GaAs1−xSbx$ $(x∼0.3)$ quantum wells with GaAs, $GaAs0.86P0.14$⁠, and $In0.5Ga0.5P$ quantum-well barriers for $80Å$ double-quantum-well heterostructures using excitation-dependent cathodoluminescence measurements at $10K$⁠. $GaAs1−xSbx$ $(x∼0.3)$ quantum wells with GaAs and $GaAs0.86P0.14$ barriers show type-II band alignment, while $GaAs1−xSbx$ $(x∼0.3)$ quantum wells with $In0.5Ga0.5P$ barriers exhibit a type-I band lineup. The type-I/type-II band alignment boundary condition as a function of the $GaAs1−xSbx$ quantum-well composition and of the barrier materials and compositions is calculated. The pseudomorphic $GaAs1−xSbx∕GaAs$ quantum-well heterointerface is estimated to have a type-II alignment. For $GaAs1−xSbx∕GaAsP$ and $GaAs1−xSbx∕InGaP$ heterostructures, both type-I and type-II alignments can occur depending on the quantum-well and barrier compositions. As the Sb composition of the quantum well increases, higher P alloy composition (in GaAsP barriers) and Ga (in InGaP barriers) composition are required in order to make the type-II to type-I transition.