Numerical drift‐diffusion simulation of Auger hot electron transport in Ingaasp/Inp double heterojunction laser diodes

Abstract

SUMMARYThis paper considers the adaptation of drift-diffusion device simulation methodology to study Auger-recombination-induced hot electron transport characteristics in InGaAsP/InP double heterostructure laser diodes. In order to model the transport behaviour of the Auger hot electrons, we decompose the conventional electron current continuity equation into two components, with one for the Auger hot electrons and the other for the low-energy electrons. These equations, which use the energy relaxation time parameter to model the dynamics of the Auger hot electrons, are then coupled with the hole current continuity equation and the Poisson equation to obtain self-consistent solutions. Results from the case studies of one-dimensional N-p-P InGaAsP/InP double heterojunction laser diodes with material composition corresponding to 1.3 pm and 1.55 pm wavelength emissions are presented. We have observed that hot electrons generated through Auger recombination inside the active region can spread into both the N-and the P-InP cladding layers.Within the drift-diffusion framework, it is demonstrated that the hot electron concentration in the N-InP cladding layer can be five orders of magnitude higher than that in the P-InP cladding layer. Because energy transport of the hot electrons is not modelled under the drift-diffusion approximation, the simulated results are discussed to highlight some of the possible limitations in using drift-diffusion physics to study Auger hot electron transport behaviour. The importance of taking energy transport into account is emphasized.