Simulation of carrier transport in quantum cascade lasers

We report a simulation study of carrier transport in quantum cascade lasers (QCLs) based on non-local transport model. In this model, drift-diffusion equations are solved with modification of current density by accounting for long-range carrier transport including quantum tunneling and hot carrier transport in the device. From the simulation results of an AlInGaAs/InP QCL at different temperatures, it is found that our model shows reasonable agreement with experiments at lower temperature when carriers are well confined while substantial deviation is observed at higher temperatures when the leakage of carriers into the continuum is significant.