266 nm AlGaN-BASED LED WITH A LOW CURRENT EFFICIENCY DROOP

A 266 nm AlGaN-based light-emitting diode (LED) displays a low efficiency droop at the temperature range from 298 to 358 K was fabricated. The maximum external quantum efficiencies were 2.71 and 2.27 % occurred at current density of 38 A cm^-2 for 298 and 318 K, respectively. The current droop (J-droop) in each of these cases was less than 7 %. Furthermore, when the temperature was increased to 358 K, the maximum EQE of 1.47 % occurred at a current density of 63.3 and 88.6 A cm^-2, and the J-droop was approximately 3.8 %. The main mechanism responsible for overcoming the J-droop was the uniform distribution of the concentrations of injected electrons and holes within the multiple quantum wells through the enhanced hole injection efficiency and inhibited the Auger recombination mechanism in an experimental setting. This LED has the potential to replace existing ultraviolet light source, such as mercury lamp for a broad range of applications including disinfection and biomedical optoelectronics.