Subband structures of strained AlSb/InAs/AlSb quantum wells

A theoretical study of the electronic subband structure in a single quantum well of strained AlSb/InAs/AlSb has been carried out. A full four-band model has been used to incorporate the effects of strain, nonparabolicity, mass renormalization, and band bending. Subband energies and cyclotron masses of the InAs quantum wells for different well widths have been calculated explicitly. It is found that the biaxial tensile strain in the InAs well increases the subband energies and lowers the electron cyclotron mass as a result of the reduction of the direct gap and the splitting of the heavy-hole–light-hole bands. The mass renormalization and barrier effects, on the other hand, increase the cyclotron mass. Space charges in the well increase the ground subband energy, and the change is greater for wider wells. Better agreement with cyclotron resonance experiments is obtained when all of the above effects are included in the calculations of the cyclotron masses.