Fabrication of Transparent Conductive Thin Film Electrodes Based on Ag Nanowire on Transparent Substrates Using the Spray Method for Photovoltaic Applications

Abstract

Materials with a remarkable combination of high electrical conductivity as well as optical transparency are playing a key role for opto-electronic devices. In addition to these specific electro-optical properties, transparent conductive materials should, for many applications, be lightweight, flexible, low-cost, non toxic and compatible with mass production techniques. In these regards, the use of Ag nanowire (Ag NW) networks appears to be a promising approach. In this study, Ag NW electrodes were fabricated by a novel spray injection method. The number of pulses was varied resulting in different network morphologies. Coatings were systematically characterised structurally, electrically and optically via SEM, four-point probe measurements and spectrophotometry, respectively. Semi uniform layers of nanowires with large haze coefficients have been obtained over large areas. Thermal annealing was shown to increase the nanowire film conductance resulting in 16 Ω/sq surface resistance and up to 73% maximal total transmittance. Films showed average optical transparencies superior to that of ITO over the 250-2500 nm range. Finally, encapsulation of Ag NWs within a matrix of ZnO nanoparticles greatly enhanced the thermal stability of these networks.