Modeling of III-nitride Light-Emitting Diodes: Progress, Problems, and Perspectives

Recent progress in III-nitride LED modeling is reviewed with the focus on physical models that provide a better understanding of such hot issues, as factors limiting the internal quantum efficiency of light emission and high-current efficiency droop, polarization doping in graded-composition III-nitride alloys and its utilization in LEDs, current crowding in LED dice and its impact on the light extraction efficiency, and optimal light conversion in white LED lamps. Specific features of III-nitride materials, their impact on the LED operation, and models accounting for these features are considered. Insufficient understanding of transport mechanisms of non-equilibrium electrons and holes and their localization in InGaN inhomogeneous active regions are discussed along with other still unsolved problems. Influence of technological factors on LED heterostructures and their operation is argued in the context of further model developments.