Near- and far-infrared quantum cascade lasers based on GaAs and GaN semiconductor materials: Devices design and MBE growth

摘要

GaAs/AlGaAs multiple quantum wells are used for realizing THz-QCLs at 3.5THz, and GaN/Al(Ga)N material systems are introduced for near-infrared (<2μm) and also large THz (9THz) emission. Non-equilibrium Green's functions (NEGF) method is developed to predict the optical gain and also to find new active region scheme. Plasma-assisted MBE is employed to successfully grow thick GaN/AlGaN sequential layers on silicon substrate.