Indium Tin Oxide-Free Transparent Conductive Electrode for GaN-Based Ultraviolet Light-Emitting Diodes

Transparent conducting electrodes are important components of highly efficient ultraviolet light-emitting diodes (UV LEDs). Indium tin oxide (ITO) is commonly used to form a current spreading layer, but its UV-range optical transparency is limited with a low sheet resistance. We demonstrate a simple solution-based coating technique to obtain large-area, highly uniform, and conductive silver-nanowire-based electrodes that exhibit UV-range optical transparency better than that of ITO for the same sheet resistance. The UV LEDs fabricated using this current spreading layer showed improved optical power emission as well as improvement in electrical properties.