Controlled carrier mean free path for the enhanced efficiency of III-nitride deep-ultraviolet light-emitting diodes.

Electron overflow from the active region confines the AlGaN deep-ultraviolet (UV) light-emitting diode (LED) performance. This paper proposes a novel approach to mitigate the electron leakage problem in AlGaN deep-UV LEDs using concave quantum barrier (QB) structures. The proposed QBs suppress the electron leakage by significantly reducing the electron mean free path that improves the electron capturing capability in the active region. Overall, such an engineered structure also enhances the hole injection into the active region, thereby enhancing the radiative recombination in the quantum wells. As a result, our study shows that the proposed structure exhibits an optical power of 9.16 mW at ∼284 wavelength, which is boosted by ∼40.5 compared to conventional AlGaN UV LED operating at 60 mA injection current.