Shape Control of Periodic Metallic Nanostructures for Transparent Conductive Films

Abstract

The transmittance limitations of metallic nanomeshes with hexagonally ordered perforations that are typically prepared by conventional nanosphere lithography (NSL) were demonstrated. Specially, the optoelectronic properties of perforated metallic films with continuously varying morphologies, ranging from spherical apertures to egg-shaped apertures, zigzag wires and approximate straight wires to metallic crosswire grids, are investigated, shedding light on the dependence of the optoelectronic properties on subtle changes of the film morphology especially on its periodicity. Further, to exploit both the high transmittance of these nanowires and the low sheet resistance of the nanomesh, we have developed a novel transparent metal electrode composed of two overlapping nanowire arrays via a stepwise ARNSL method. This sophisticated electrode has an increased optoelectronic performance with a sheet resistance of 100 ω sq and an average optical transmittance of 80% and is hopeful to be further improved. The stepwise ARNSL method addresses the challenges of fabricating intercrossed pattern from parallelly aligned conductive wires arrays, which are significant in constructing nanowire devices. These findings provide useful insights in the design and fabrication of unique 2D metallic electrodes for potential high-performance transparent electrode application in the transparent electronics.