Efficient calculation of the scattering rates in valence-band quantum wells

An effective approach for calculating the (phonon) scattering rate in valence-band quantum wells is presented. The valence-subband structure and the wave functions are obtained using the multiband effective-mass approximation. The subband structure is modeled by piecewise second-order polynomials while its anisotropy is neglected. The effect of the central-cell symmetry is incorporated in the calculation by effectively including the overlap integral in the transition probability given by the Fermi golden rule. For a valence-band quantum well, the relaxation rates due to the polar LO-phonon-, nonpolar LO-phonon-, and LA-phonon-scattering mechanisms at zero temperature are calculated. Due to the higher density of states in valence-band quantum wells, the calculated scattering rates are generally higher than the rates in similar structures based on conduction-band quantum wells.