Electronic Energy Levels in In sub x Ga sub (1-x) As/Inp Strained Layer Superlattice.

We use intentionally lattice mismatched superlattices of In sub x Ga sub (1-x) As / InP , where 0.3 x 0.8, to study the energy levels of confined particle states characteristic of strain layer superlattices. We demonstrate that the energy difference between the lowest heavy and light hole exciton levels of In sub x Ga sub (1-x) As quantum wells changes continuously with strain. For x 0.44 the exciton levels switch poritions so that the light hole becomes the lower energy state. The experimental results can be modeled with very high accuracy over the entire range of In compositions studied with a phenomenological deformation potential theory.