Electronics and optical properties of quantum well interdiffusion with valence band mixing

The interdiffusion of III-V compound semiconductor quantum well structure has received much attention recently. Materials around 1.55 μm band-gap wavelength are required to produce a variety of optoelectronic devices. The effects of interdiffusion on the confinement potential, the valence bands structure, and the material gain of In_0.53Ga_0.47As/InP quantum well have been analyzed theoretically based on the different types of sublattices interdiffusion. The interdiffusion process is described by Fick's law with constant diffusion coefficients in both well and barrier layers. An approach based on the effective Hamiltonian is used to calculate the subband structure which includes the effect of valence band mixing. The material gain is also calculated from the subbands structure using the Fermi Golden rule. The results show that enhancement of the material gain by 42% can be obtained by the group-III interdiffusion at a diffusion length of 30 Å. A large 240 meV red shift of the peak gain from 0.87 to 0.63 eV is also obtained. © 1998 Elsevier Science B.V. All rights reserved.