Reflective Silver Thin Film Electrodes from Commercial Silver(I) Triflate via Aerosol-Assisted Chemical Vapor Deposition

Abstract

The growth of metallic silver films by aerosol-assisted chemical vapor deposition at atmospheric pressure for use as thin film electrodes or reflective layers in optoelectronic stacks has been studied using the self-metallization of silver(I) trifluoromethanesulfonate (silver(I) triflate, [Ag(SO3CF3)]) during chemical vapor deposition under nitrogen, air and 5% H2/N2. The deposition behaviour of the triflate from a methanolic solution was observed with respect to film thickness between 170 and 240 nm, while the dependence of electrical resistivity between ρ = 2.8 × 10 0 and 5.0 × 10-5 Ω cm on nanocrystallite diameter between 38 and 44 nm indicated a grain boundary-limited charge carrier propagation mechanism arising from insular film growth. Furthermore, increased nanocrystallite size reduced specular optical reflectance from 11 to 3 %. The thermal stability of silver(I) triflate as compared with other silver precursors enabled deposition at elevated temperatures with maximum growth rates of 11 nm min-1 , representing a manifold increase over many previously reported Ag thin film chemical vapor deposition processes on non-metallic substrates. Nanocrystallite diameter was directly proportional to film thickness, such that control over thickness enabled control over surface texture, electrical resistivity and specular optical reflectivity.