Eur. Phys. J. B 65, 195-206 (2008)
https://doi.org/10.1140/epjb/e2008-00355-x

Photon emission induced by elastic exciton-carrier scattering in semiconductor quantum wells

¹ LASMEA, UMR CNRS-Université Blaise Pascal 6602, 24 Avenue des Landais, 63177 Aubière Cedex, France
² School of Physics, University of Exeter, Exeter EX4 4QL, UK
³ Physics, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK

Corresponding author: ^a ouerdane@ganil.fr

Received: 15 June 2008
Published online: 23 September 2008

Abstract

We present a study of the elastic exciton-electron (X–e and exciton-hole (X–h) scattering processes in semiconductor quantum wells, including fermion exchange effects. The balance between the exciton and the free carrier populations within the electron-hole plasma is discussed in terms of ionization degree in the nondegenerate regime. Assuming a two-dimensional Coulomb potential statically screened by the free carrier gas, we apply the variable phase method to obtain the excitonic wavefunctions, which we use to calculate the 1s exciton-free carrier matrix elements that describe the scattering of excitons into the light cone where they can radiatively recombine. The photon emission rates due to the carrier-assisted exciton recombination in semiconductor quantum-wells (QWs) at room temperature and in a low density regime are obtained from Fermi's golden rule, and studied for mid-gap and wide-gap materials. The quantitative comparison of the direct and exchange terms of the scattering matrix elements shows that fermion exchange is the dominant mechanism of the exciton-carrier scattering process. This is confirmed by our analysis of the rates of photon emission induced by electron-assisted and hole-assisted exciton recombinations.