Calculations of hole subbands in semiconductor quantum wells and superlattices

Abstract

Calculations of hole subbands in GaAs-AlGaAs quantum wells and superlattices are performed within the envelope-function approach, with full inclusion of the degeneracy and warping of the bulk valence bands described by the Luttinger Hamiltonian. Boundary conditions including effective-mass discontinuities at the interfaces are adopted. The subband dispersion is characterized by large nonparabolicities, which strongly affect the density of states of the valence subbands and the joint density of states for transitions to the conduction subbands. The validity of some approximations, the sensitivity of the hole subband structure to the valence-band-edge discontinuity, and a comparison to optical experiments are briefly discussed.