Effect of current injection efficiency on efficiency-droop in InGaN quantum well light-emitting diodes

In this paper, the current injection efficiency (¿_injection) and internal quantum efficiency (¿_IQE) of InGaN QWs are investigated. Due to the existence of the polarization field in the InGaN QW, the band bending of the band edge potential leads to thermionic carrier escape from InGaN QW GaN barrier regions. The ¿_injection is the fraction of injected current that recombines in the QW active region, and the radiative efficiency (¿_Radiative) is the fraction of recombination current in QW that recombines radiatively. The ¿_IQE can be expressed as the product of ¿_injection and ¿_Radiative. Here, the current injection efficiency model is developed based on current continuity relation for drift and diffusion carrier transport across the barrier, and the radiative efficiency model is based on self consistent 6-band k·p method.