Study of Au nanoparticles/ITO ohmic contacts to p-type GaN

P‐type ohmic contact between Au nanoparticles/ITO and p‐GaN during heat treatment is reported. Optimal conditions are selected to minimize the lowest specific contact resistance to 1.66 × 10–3 Ω cm2, as determined by the transmission line model (TLM) after heat treatment process at an alloying temperature of 600 °C for 10 min in air. Au nanoparticles/ITO bi‐layers are also applied to GaN‐based LEDs to form an electrode with a p‐type ohmic contact. Typical I–V characteristics of the GaN‐based LEDs with an ohmic contact layer of Au nanoparticles/ITO exhibit a forward‐bias voltage of 3.43 V at an injection current of 20 mA. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)