The efficiency of GaN/AlGaN p-n heterostructures in UV spectral range

GaN/AlGaN p-n heterostructures emitting in UV spectral range obtained by HVPE approach were investigated. It was shown that the peak wavelength of UV LEDs was in the range of 360-380 nm with FWHM of 10-13 nm. At operating current of 20 mA, the active region temperature T_j was 43°C, the output optical power and efficiency - 1.14 mW and 1.46%, respectively. The model based on corpuscular Monte Carlo method for calculation of the light extraction index was presented. The simulation results allow us to propose the ways to increase the efficiency of UV LEDs: surface interfaces texturing, optimization of the design of heterostructures, and the use of lenses. (paper)