Modeling of type-II InAs/GaSb superlattices using an empirical tight-binding method and interface engineering

We report the most recent work on the modeling of type-II InAs/GaSb superlattices using the empirical tight binding method in an ${\mathrm{sp}}^3{s}^{*}$ basis. After taking into account the antimony segregation in the InAs layers, the modeling accuracy of the band gap has been improved. Our calculations agree with our experimental results within a certain growth uncertainty. In addition, we introduce the concept of ${\mathrm{Ga}}_x{\mathrm{In}}_{1-x}$ type interface engineering in order to reduce the lattice mismatch between the superlattice and the GaSb (001) substrate to improve the overall superlattice material quality.