Numerical investigation on the carrier transport characteristics of AlGaN deep-UV light-emitting diodes

Carrier transport characteristics of AlGaN-based deep-ultraviolet light-emitting diodes (LEDs) are theoretically investigated. Simulation results reveal that hole transport/injection may be severely obstructed by the large potential barrier at the p- electron-blocking layer/p-GaN interface. Under this circumstance, the slope efficiency degrades and electron leakage increases accordingly. By inserting the AlGaN interlayers to form band-engineered staircase p-region, both the transport/injection of holes and I-V characteristic are improved. Moreover, the LED characteristics become less sensitive to the polarization field, which is beneficial for obtaining high LED performance with the LED of high crystalline quality.