Polarization‐Engineered Barrier Designs and Field Reversal Strategies for Improved Carrier Confinement in N‐Polar Thin‐Film Aluminum Gallium Nitride Deep‐Ultraviolet Light‐Emitting Diodes

Conventional Ga‐polar aluminum gallium nitride (AlGaN) deep‐ultraviolet (UV) light‐emitting diodes (LEDs) suffer from polarization‐induced carrier separation and severe electron leakage, which limit device efficiency. In this regard, we present an N‐polar AlGaN‐based UV LED integrating a band‐engineered active region designed to overcome the limitations of conventional AlGaN UV‐LEDs. The proposed N‐polar LED incorporates engineered quantum barriers that reduce electron thermal velocity and mean free path, significantly minimizing electron leakage. Additionally, the N‐polar orientation helps mitigate the quantum‐confined Stark effect and enhances carrier overlaps within the quantum wells. As a result, the internal quantum efficiency and output power of the proposed N‐polar LED structure have been improved significantly. The optimized device achieves ∼14 mW at 60 mA, achieving a peak IQE of 43% with low turn‐on voltage of ∼3.85 V and 16.2% efficiency droop, which is 2x power improvement over conventional LEDs.