Impact ionization coefficient of excitons in n-GaAs
The impact ionization coefficient of excitons is investigated in n-GaAs both experimentally and theoretically. The experimental results obtained by a time-correlated single-photon counting technique are analysed by using the time-dependent differential rate and Boltzmann equations. It is found that in moderately doped n-GaAs at low temperatures the electron distribution function and impact ionization coefficient of excitons are affected by the impact ionization of neutral donors as an inelastic scattering mechanism.