Enhanced broadband transmission through structured plasmonic thin films for transparent electrodes

Abstract

Periodic arrays of subwavelength holes in plasmonic thin films can provide for large broadband transmission in the near-infrared spectrum. The optical transmission properties of these thin films with respect to the film thickness, size, and shape of the holes and the period of the arrays was systematically investigated using finite difference time domain computations. Structured gold and silver films of 20-nm thickness can provide for up to 90% transmittance at near-infrared wavelength, thereby rendering them suitable as transparent conducting electrodes for near-infrared emitters or sensors and photovoltaic applications.