Eur. Phys. J. B (2012) 85: 67
https://doi.org/10.1140/epjb/e2012-20887-6

Regular Article

Phonon and electron-hole plasma effects on binding energiesof excitons in wurtzite GaN/In_xGa_1−xN quantum wells

¹ School of Physical Science and Technology, Inner Mongolia University, Key Laboratory of Semiconductor Photovoltaic Technology at Universities of Inner Mongolia Autonomous Region, Hohhot 010021, P.R. China
² Department of Physics, College of Sciences, Inner Mongolia University of Technology, Hohhot 010051, P.R. China

^a e-mail: slban@imu.edu.cn

Received: 1 November 2011
Received in final form: 21 December 2011
Published online: 13 February 2012

Abstract

The binding energy of an exciton screened by the electron-hole plasma in a wurtzite GaN/In_xGa_1−xN quantum well (in the case of 0.1 < x < 1 within which the interface phonon modes play a dominant role) is calculated including the exciton-phonon interaction by a variational method combined with a self-consistent procedure. The coupling between the exciton and various longitudinal-like optical phonon modes is considered to demonstrate the polaronic effect which strongly depends on the exciton wave function. All of the built-in electric field, the exciton-phonon interaction and the electron-hole plasma weaken the Coulomb coupling between an electron and a hole to reduce the binding energy since the former separates the wave functions of the electron and hole in the z direction and the later two enlarge the exciton Bohr radius. The electron-hole plasma not only restrains the built-in electric field, but also reduces the polaronic effect to the binding energy.