Non-equilibrium electronic distribution within one period of InP-based quantum cascade lasers

A joint theoretical and experimental investigation on the influence of the doping concentration in InP-based quantum cascade lasers on the device performance is presented. The theoretical analysis is based on a Monte Carlo simulation that includes both electron-phonon and electron-electron scattering and explicitly considers non-equilibrium phonon effects. Good agreement is found between the experimental data and the Monte Carlo results, which clarify the role played by doping in the alignment of the electron levels and in the achievement of population inversion.