Simulation of Confined and Interface Phonons Scattering in Terahertz Quantum Cascade Laser

We have performed the calculation of resonant-phonon transition in a terahertz quantum cascade laser. The electron wavefunctions and energy levels are obtained by solving the Schrödinger and Poisson equations self-consistently. The scattering rates of the confined, interface, and bulk phonons are calculated by using the Fermi golden rule. It has been shown that the confined phonon scattering is comparable to the interface phonon scattering and should be taken into consideration in the calculation.