Doping-induced type-II to type-I transition and mid-IR optical gain in InAs/AlSb quantum wells

Abstract

We study effects of modulation doping in a type-II quantum well by performing a self-consistent band structure calculation using the 8-band k · p theory. We show that modulation doping can convert a type-II quantum well structures into type-I. The associated band bending and charge redistribution lead to strong interband transition in such type-II structures comparable to that of a type-I quantum well. The results are shown for InAs/AlSb quantum well, where TM mode optical gain can be as high as 4000cm −1 . We also studied effects of doping on differential gain.