Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2012 · 39 citations · 20 references
EngineeringElectrical EngineeringPhysicsOptoelectronicsSemiconductor DevicesSemiconductor MaterialsLight-emitting DiodesOptoelectronic DevicesOptoelectronic MaterialsSemiconductor Device MaterialsSemiconductor HeterostructuresSemiconductor PhysicsCurrent DensityHeterostructure DesignHeterostructure OptoelectronicsHeterostructuresInternal Quantum EfficiencyLight-emitting DevicesQuantum EfficiencySemiconductor Light-emitting Materials
The paper discusses various factors affecting internal quantum efficiency (IQE) of state-of-the-art III-nitride lightemitting diodes (LEDs). A general figure of merit for LED heterostructures, namely the quality factor, is proposed on the basis of a simple recombination model, which enables comparison of overall performances of the structures either emitting light at different wavelengths or having substantially different designs. The relationships between the quality factor, maximum value of IQE, and IQE droop with the current density are revealed. Some ways for IQE improvement and reducing its droop are considered. Among them, the use of short-period superlattice (SPSL) active regions is found to be quite promising. The operation of such structures and their properties are examined in detail by simulations accounting for quantum corrections to electron and hole transport within the quantum-potential concept.
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