InGaN/GaN Quantum Dot Visible Lasers
The demonstration of quantum dots (QDs) with emission covering the entire visible spectrum is important for many applications including solid-state lighting. For facilitating the development of quantum dot-based (QD-based) III-N visible lasers, it is crucial to have a comprehensive model that is able to describe the measured data and extract physical parameters which are not readily available in the literature or directly measured. When the carriers enter the system, either through optical or electrical pumping, the spatially separated electron-hole pairs (EHPs) form another electrical dipole in the opposite direction of the polarization field. The screening effect in self-assembled QDs (SAQD) structures in the z direction is actually the same as that in quantum wells (QWs). However, it is the extra confinement in the transverse direction that stops the carriers from leaving the quantum structure and recombining at defect centers. Multiple dot layers are typically grown in the active region of lasers to maximize the optical gain and modal confinement factor.