Optics Express · 2010 · 28 citations · 22 references
EngineeringElectrical EngineeringMaterials ScienceElectronic MaterialsOptoelectronicsSemiconductor MaterialsIii-v SemiconductorsLight-emitting DiodesSemiconductor Device MaterialsWide Band Gap SemiconductorsWide-bandgap Semiconductor DevicesWide-bandgap SemiconductorsDefect DensityDefect Recombination CentersHigh PerformanceLight-emitting DevicesNonradiative RecombinationNonradiative Recombination CentersQuantum EfficiencyRecombination Centers
GaN-based light-emitting diodes (LEDs) grown on c-plane vicinal sapphire substrates are fabricated and characterized. Based on the material quality and electrical properties, the LED with a 0.2 degrees tilt sapphire substrate (device A) exhibits the lowest defect density and high performance, while the LED with a 1.0 degrees tilt sapphire (device D) exhibits the highest one. At 2 mA, the extremely enhanced output power of 23.3% indicates of the reduction of defect-related nonradiative recombination centers in active layers for the device A. At 60 mA, the improved value is up to 45.7%. This is primarily caused by the formation of indium quantum dots in MQW which provides an increased quantum efficiency.
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