Modeling of III-Nitride Multiple-Quantum-Well Light-Emitting Structures

Abstract

Spatial inhomogeneity of carrier injection across the multiple-quantum-well (MQW) active region of a semiconductor light emitter can impose severe limitations on the device efficiency. In III-nitride-based devices, the large disparity of electron and hole transport and the excessive depth of active QWs trigger the process of inhomogeneous QW injection which is further aggravated by strong dependence of QW radiative characteristics on the QW injection conditions due to 1) intra-QW screening of polarization fields in polar and semipolar materials, 2) phase-space filling effect in lowest QW subbands at higher levels of carrier injection, and 3) exceedingly nonequilibrium character of the electron and hole populations in deep QWs. All these tendencies become more pronounced in longer wavelength emitters. The residual QW charges provide strong feedback to the QW injection conditions, thus requiring a high level of self-consistency between the active region transport simulation and the QW emission modeling.