A simple quasiclassical treatment of bias-dependent carrier capture in quantum wells

Capture of carriers in semiconductor quantum wells (QWs) plays an important role in quantum well-based light emitting diodes (LEDs), laser diodes (LDs) and photodetectors, and in studies of QW structures and devices by photoluminescence (PL) and cathodoluminescence (CL). Carrier injection by forward bias of quantum well LEDs and LDs introduces electrons and holes from larger bandgap cladding layers into single or multiple QWs. In PL and CL studies of QW structures and devices, carriers excited in cladding layers diffuse or drift to QWs under different bias conditions, and captured carriers produced QW luminescence. To better understand bias-dependent CL experiments on II-VI QW-LEDs, a simple, quasiclassical treatment of bias-dependent carrier capture has been developed. Capture probabilities for electrons, holes and excitons have been considered. The assumptions and results of this treatment are described.