Preparation and property optimization of silver-embedded FTO transparent conductive thin films by laser etching and coating AZO layer

Abstract

Preparation and property optimization of silver (Ag)-embedded fluorine-doped tin oxide (FTO) films were achieved based on laser etching, sputtering Ag layers, furnace annealing, sputtering aluminum-doped zinc oxide (AZO) layers and laser annealing. Specifically, a nanosecond pulsed laser (λ = 532 nm) was used to etch grooves on FTO films before sputtering 5-nm-thick Ag layers, with an aim for enabling the Ag nanoparticles from the furnace-annealed Ag layers to be intensively embedded in the grooves under the thermal-induced dewetting effect. The optimal laser fluence for laser etching and temperature for furnace annealing were found to be 0.4 J/cm2 and 300 °C, respectively. The as-obtained Ag-embedded FTO film exhibited significantly improved optical and electrical properties, being attributed mainly to the decreased coverage area of the Ag nanoparticles on the FTO film surface and the furnace annealing effect. The subsequently sputtered 10-nm-thick AZO layer suppressed the internal light reflection from the Ag nanoparticles, and laser annealing further facilitated grain growth in the film. Therefore, the resulting film had the best comprehensive property with the highest figure of merit of 20.94 × 10–3 Ω–1, which was much higher than that of the original FTO film (7.65 × 10–3 Ω–1). This work may provide a new combined processing method for high-performance transparent conductive films.