Localization landscape theory of disorder in semiconductors. III. Application to carrier transport and recombination in light emitting diodes

摘要

This paper introduces a novel method to account for quantum disorder effectsinto the classical drift-diffusion model of semiconductor transport through thelocalization landscape theory. Quantum confinement and quantum tunneling in thedisordered system change dramatically the energy barriers acting on theperpendicular transport of heterostructures. In addition they lead topercolative transport through paths of minimal energy in the 2D landscape ofdisordered energies of multiple 2D quantum wells. This model solves the carrierdynamics with quantum effects self-consistently and provides a computationallymuch faster solver when compared with the Schr\"odinger equation resolution.The theory also provides a good approximation to the density of states for thedisordered system over the full range of energies required to account fortransport at room-temperature. The current-voltage characteristics modeled by3-D simulation of a full nitride-based light-emitting diode (LED) structurewith compositional material fluctuations closely match the experimentalbehavior of high quality blue LEDs. The model allows also a fine analysis ofthe quantum effects involved in carrier transport through such complexheterostructures. Finally, details of carrier population and recombination inthe different quantum wells are given.