Electric field dependence of intrasubband polar-optical-phonon scattering in a quantum well

Abstract

The electric field dependences of intrasubband polar-optical-phonon scattering for electrons and holes in a semiconductor quantum well are studied theoretically using a simple infinite well model. It is found that the polar-optical-phonon scattering rates are enhanced with an applied electric field. They are higher for heavy holes for all ranges of electric fields, and the electric field dependence of the hole–polar-optical-phonon scattering is much stronger than that of the electron–polar-optical-phonon scattering. The higher subbands have, in general, weaker electron-phonon scattering rates and electric field dependences than those of the ground state. The tunneling effect in a finite well is also discussed. It is suggested that recent experimental results of the field-dependent line broadening of near band-edge optical absorption can be attributed, at least qualitatively, to the dominance of heavy-hole–polar-optical-phonon interaction and heavy-hole tunneling.