AlGaN Polarized\nUltrathin Tunneling Junction Deep\nUltraviolet Light-Emitting Diodes

Deep ultraviolet light-emitting diodes (DUV-LEDs) are\nhindered\nby optical losses and high operating voltages, primarily due to p-contact\nlayers such as light absorption in p-GaN or high operating voltages\nlinked to inferior hole injection caused by high acceptor ionization\nenergy for p-AlGaN and large bulk resistance in AlGaN-based tunneling\njunctions (TJs). To overcome these challenges, we introduce a transparent\nAlGaN polarized ultrathin tunneling junction (PUTJ). This innovative\ndesign features a low-bulk-resistance TJ with ultrathin p- and n-regions\n(20 nm), incorporating an intrinsic AlGaN interlayer that leverages\npolarized electric fields to enhance the interband tunneling injection\nof holes. Benefiting from the significantly reduced TJ thickness,\nthe 273 nm PUTJ DUV-LED achieves minimal absorption losses and a record-low\noperating voltage of 5.8 V at 30 A/cm<sup>2</sup>. This advancement\nrepresents a substantial leap forward in the development of efficient\nDUV light sources, potentially revolutionizing III-nitride optoelectronics\nwith reduced optical and electrical losses at the p-contact layer.