Ultrasonic spray coating of gold nanoparticles: A comprehensive study on the surface coverage and position of Au-NPs in the hole injection layer of OLEDs for an optimized luminous efficacy

OLEDs consisting of Au-NPs sandwiched between anode and hole injection layer, and close to an active layer inside PEDOT:PSS is fabricated by Ultrasonic Spray Coating (USSC). Optimized surface coverage of Au-NPs on ITO facilitates efficient charge injection and an optimized position of the Au-NPs away from the active layer accelerates the radiative recombination. Obtained results indicate that USSC could effortlessly tune the surface coverage and the vertical position of the Au-NPs to enhance the OLED’s efficacy. This paves the way for the fabrication of large area, high efficient OLEDs with USSC.