Indium-Tin-Oxide-Free organic light-emitting device

Sapphire substrates coated with a gold (Au) layer in place of indium-tin-oxide (ITO) on glass substrates are used as hole-injecting anodes in organic light-emitting devices (OLEDs). Due to the unique quality of the sapphire/Au interface and match of Au work function with the highest occupied molecular orbital level of the adjacent hole transport layer (HTL), and the smoothness of the interface, he ITO-free OLED, achieved an increase in current efficiency by more than a factor of three.