Influence of separate confinement heterostructures on the effective carrier recombination coefficient in quantum well laser structures

Abstract

We analyzed the carrier recombination coefficient of quantum well laser structures by combining two-level ambipolar rate equations and a carrier diffusion equation for the separate confinement heterostructure (SCH) layer. We derived a new analytical expression for the effective carrier recombination coefficient (Beff) in quantum well laser structures. From our analysis, we found out that the dominant factor that determines Beff is not the diffusion across the SCH layer but the ratio of confined carriers in the well to the total carriers in both the well and the SCH layers. Our new expression well explained the measured results of 1.3 μm strained-layer quantum well lasers with SCH layers of different thicknesses.