AlGaN Polarized Ultrathin Tunneling Junction Deep Ultraviolet Light-Emitting Diodes

Deep ultraviolet light-emitting diodes (DUV-LEDs) are hindered by optical losses and high operating voltages, primarily due to p-contact layers such as light absorption in p-GaN or high operating voltages linked to inferior hole injection caused by high acceptor ionization energy for p-AlGaN and large bulk resistance in AlGaN-based tunneling junctions (TJs). To overcome these challenges, we introduce a transparent AlGaN polarized ultrathin tunneling junction (PUTJ). This innovative design features a low-bulk-resistance TJ with ultrathin p- and n-regions (20 nm), incorporating an intrinsic AlGaN interlayer that leverages polarized electric fields to enhance the interband tunneling injection of holes. Benefiting from the significantly reduced TJ thickness, the 273 nm PUTJ DUV-LED achieves minimal absorption losses and a record-low operating voltage of 5.8 V at 30 A/cm². This advancement represents a substantial leap forward in the development of efficient DUV light sources, potentially revolutionizing III-nitride optoelectronics with reduced optical and electrical losses at the p-contact layer.