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

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.