Carrier relaxation and luminescence polarization in quantum wells

Abstract

A theory of polarization of luminescence in doped and undoped quantum wells is constructed taking into account the relaxation processes of photoexcited electrons and holes. The hole momentum relaxation by acoustic-phonon interaction yields spin relaxation through the spin mixing of the hole band states, resulting in incomplete spin depolarization in quantum wells. Our theory of hole-phonon interaction in symmetric quantum wells leads to the concept of relaxation through two channels conserving or changing the parity of the hole state. Calculation of the polarization spectra for undoped, n-type-doped, and p-type-doped GaAs/${\mathrm{Al}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Ga}}_{\mathit{x}}$As quantum wells produces an explanation of all the observed features in the spectra.