On the enhancement of carrier injection efficiency by employing AMnN last quantum barrier in 277 nm ultraviolet light-emitting diodes

摘要

The AlInN last quantum barrier (LQB) has been employed instead of conventional AlGaN in ultraviolet light-emitting diodes (UV LEDs). The simulation results reveal that p-doped AlInN and un-doped AlInN LQB effectively suppressed electron leakage and facilitated the movement of holes to the active zone, which is greatly attributed to the higher conduction band offset and lower valence band offset of the AlInN alloy. Moreover, AlInN has reduced the lattice mismatching, leading to a decrease in the induced polarization field. Hence, the internal quantum efficiency (IQE) and the radiative recombination rate, with the AlInN LQB, has been increased by 54% and 260%, respectively, as compared with conventional AlGaN-based LQB LEDs. Importantly, the AlInN LQB not only increased the IQE but also alleviated the efficiency droop dramatically. Additionally, the emission spectrum at 277 nm has been remarkably enhanced as compared with conventional LEDs. Thus, based on these results, it was found that the un-doped AlInN LQB is a feasible route for achieving efficient UV LEDs.