Performance enhancement of blue light-emitting diodes by adjusting the p-type doped last barrier

Blue light-emitting diodes (LEDs) with different p-doping concentrations in the last barrier have been studied numerically. The energy band diagrams, carrier concentrations, internal quantum efficiency and light output power are investigated using APSYS software. The simulation results show that the LED structure with p-doping in the last barrier has a better hole-injection efficiency and confinement of electron leakage over the structure with the last undoped GaN barrier due to enhancement of the holes’ injection and the electrons’ confinement. As a result, the efficiency droop is markedly improved, and the light output power is greatly enhanced when a larger p-doping amount is centralised in the last barrier.