Activationless electron and hole recombination rate in semimetallic semiconductor quantum wells

We present numerical calculations of electron–hole recombination in n-type and p-type semimetallic quantum wells made of InAs and GaSb semiconductors. The overlap between the conduction and valence bands in these wells gives rise to an activationless generation and recombination process that does not require an extra excitation particle such as a phonon or a photon. We calculate this recombination rate using the transfer matrix method with a 8×8 k·p matrix Hamiltonian which takes into account the nonparabolicity and anisotropy of the band structure. Our calculations show that the recombination rates increase with increasing electron and hole energies. We also investigate the effect of an externally applied electrical potential on the recombination rates and consider the case when the transition coefficient, T(E,k⊥), depends on k⊥.