The electrical and optical properties of direct-patternable SnO₂ thin films containing Pt nanoparticles at various annealing temperatures

The optical and electrical characteristics of SnO₂ films with 0.02at% Pt nanoparticles were studied after annealing at various temperatures. Pt nanoparticles were synthesized by a methanol reduction method and their size was limited to 3nm on average using PVP [poly(N-vinyl-2-pyrrolidone)] as a protecting agent. The electrical conduction of the SnO₂ films was enhanced by the introduction of Pt nanoparticles without degradation of optical transmittance. The resistivity and transmittance of the SnO₂ films with and without Pt nanoparticles after annealing at 700°C were 2.9×10^-2Ωcm and 86.45%, and 1.5×10^-1Ωcm and 85.75%, respectively. The observed enhancement in electrical properties was attributed to an increase in carrier concentration due to the addition of Pt nanoparticles. The fact that almost no change in transmittance was observed is explained by the small quantities produced and small particle sizes of the Pt nanoparticles. Well-defined 30-μm-wide direct-patterned SnO₂ films containing Pt nanoparticles were formed by photochemical metal-organic deposition using a simple process including a photosensitive starting precursor, UV exposure, and removal of the un-patterned area with solvent rinsing.