Thin Metal Transparent Conductive Electrodes Formed by Oblique-Angle Deposition

Oblique-angle deposition (OAD) was recently developed for the fabrication of functional thin films with varying porosity and refractive index. In this study, OAD is used to fabricate excellent thin-metal transparent conductive electrodes (Thin-TCEs) with an optical transmittance of >93% at wavelengths of 450–550 nm, and sheet resistance of ≈14 Ω sq^{– 1}. The process involved the deposition of a thin Ni (5 nm)/Au (5 nm) bilayer with a tilt angle of 45°, and subsequent thermal annealing in ambient O₂ to produce a 10 nm-thick nickel oxide layer with very uniformly distributed Au nanoparticles, afforded by the enhanced interaction between the ambient gas and the metallic film. The application of the Thin-TCE to III-nitride light-emitting diodes (LEDs) produced 15.4% higher output power and 0.05 V lower forward voltage compared to the reference LEDs. These results indicate that the Thin-TCE is a promising potential replacement for the ITO TCE currently used in III-nitride LEDs and organic optoelectronic devices, especially considering their fast and cheap fabrication process, availability for mass production, and better electrical and optical properties.