Continuous copper film structures with broadband optical transparency

Abstract

Highly conductive metal films with optical transparency are significantly important for the rapid development of optoelectronic applications. However, the opacity of continuous metal films or narrow transparent bandwidth of metal nanostructures greatly limits their applications. Here, we predict a continuous copper (Cu) film with a broadband optical transparency (BOT) window via using a plasmonic array (PA) and an ultra-thin optical cavity (OC) to respectively act as the light input and output couplers. The transparent bandwidth with the transmittance above 90% reaches 330nm in the optical regime. In particular, the achieved transparency properties are with high scalability. Moreover, the introduced closely packed PA and the OC could be fabricated straightforward by the colloidal self-assembly method and standard deposition methods. These optical and structural features hold the predicted BOT structure to be a powerful candidate for the transparent and conductive optoelectronic devices.