Numerical study of polarization-doped AlGaN ultraviolet light-emitting diodes

•Graded AlGaN layer is inserted into the AlGaN UV LEDs.•Polarization-induced p-type doping has important effect on hole injection efficiency.•The enhanced injection efficiency of electron and hole is obtained.•The designed UV LED shows improved performance compared with conventional LED.

The AlGaN-based ultraviolet light-emitting diodes (UV LEDs) with specific design of polarization-induced p-type doping are investigated numerically. The proposed polarization-doped UV LEDs with different Al content graded AlGaN layers exhibit significant improvement for the light output power and carrier injection efficiency compared with the conventional AlGaN UV LED. The enhanced performance for polarization-doped UV LED is explained by the simulated energy band diagrams, distribution of carrier concentration and radiative recombination rate in the quantum wells.