Band Structure, Optical Transition, and Optical Gain of Type-II InAs(N)/GaSb Quantum Wells Laser Diodes Modeled Within 16-Band and 14-Band Model

We have used both 16-band and 14-band kp Hamiltonians to investigate electronic band-structure, optical gain and transitions of two type-II quantum wells with InAs and InAs_0.98N_0.02 as the active layers surrounded by a GaSb layer, respectively. The obtained results are discussed in the context of the importance of the contribution of the p-type conduction band nonparabolicity. The results are given explicitly in the [001] and [111] directions. We have also reported a comparison between the results obtained within the 16-band and 10-band kp models in terms of optical gain and threshold current density for [111]-oriented laser structure. For typical carrier concentration of 8 × 1012 cm^-2 at 300 K, we achieved an emission wavelength of ~2.55 μm with a peak gain of order 1400 cm^-1 obtained within 16-band kp model while for the 10-band kp model, a peak gain of order 564 cm^-1 is reached providing an emission wavelength at ~2.04 μm.