Performance enhancement of AlGaN-based UV-LEDs inserted with a pin-doped AlGaN layer between the active region and electron-blocking layer

The AlGaN-based deep ultraviolet light-emitting diodes with an Mg-Si pin-doped AlGaN layer inserted, between the active region and electron-blocking layer, have been systematically investigated by APSYS software. The energy band diagram, carrier distribution, and radiative recombination are studied. When compared with the conventional deep ultraviolet light-emitting diodes, the simulation results demonstrate that the proposed structure has effectively improved the output power, internal quantum efficiency, carrier concentrations, and radiative recombination rate. Based on the analysis of electrical and optical properties, and the performance improvements provided by using a pin-doped layer, we conclude that they are mainly attributed to the suppression of quantum-confined Stark effect as well as electron confinement and hole-injection enhancement in the active region effectively. In addition, the optimized thickness of this insert layer has been achieved after detailed research. As a result, the AlGaN-based deep ultraviolet light-emitting diodes with 10-nm-thick insert layer demonstrate improved performance.