Al composition dependency of interface phonon in the wurtzite quantum cascade laser

Abstract:

The interface(IF) phonons of the wurtzite quantum cascade lasers(QCL) are investigated using the transfer-matrix method(TMM).The IF modes are presented in the longitudinal optical-phonon frequency for the Al0.2Ga0.8N/GaN and Al0.15Ga0.85N/GaN QCLs,and two IF modes can be changed into other modes if their wave numbers are less than the special values.Owing to the more dispersive properties of IF phonons with the increasing Al composition,the scattering rates in both QCLs increase with the Al composition.