Novel laser-based metasurface fabrication process for transparent conducting surfaces

Transparent conducting film provides key functions for various optoelectronic devices. Existing manufacturing processes of a transparent conducting film are usually very costly in terms of materials or processing time. The goal of this research is to develop a new surface engineering method for low-cost and high-throughput fabrication of large-size, transparent conducting glass windows. A novel laser-based metasurface fabrication process is presented in this work, which comprises two steps: (1) evaporating the glass substrate by an ultrathin metal film with a thickness on the order of 10 nm and (2) laser patterning the coated surface using a nanosecond pulsed laser (1064 nm wavelength) with a typical feature size of hundreds of micrometers. During the second step of the laser scanning process using an appropriate pulse energy density, the metal film absorbs most of the laser pulse energy and is patterned through laser material ablation, while little damage will be induced on the substrate since its absorptivity at the laser wavelength is low. Experimental results have shown that a transparent conducting film with an average visible transmittance of ∼67% and a sheet resistance of ∼20 Ω/sq can be successfully fabricated. Compared with the other existing methods, this novel laser surface patterning process significantly improves the processing efficiency and reduces the production cost that renders practical treatment of glass materials or transparent ceramics to produce transparent conducting surfaces.