Direct-patternable SnO₂ thin films incorporated with conducting nanostructure materials

There have been many efforts to modify and improve the properties of functional thin films by hybridization with nano-sized materials. For the fabrication of electronic circuits, micro-patterning is a commonly used process. For photochemical metal-organic deposition, photoresist and dry etching are not necessary for microscale patterning. We obtained direct-patternable SnO₂ thin films using a photosensitive solution containing Ag nanoparticles and/or multi-wall carbon nanotubes (MWNTs). The optical transmittance of direct-patternable SnO₂ thin films decreased with introduction of nanomaterials due to optical absorption and optical scattering by Ag nanoparticles and MWNTs, respectively. The crystallinity of the SnO₂ thin films was not much affected by an incorporation of Ag nanoparticles and MWNTs. In the case of mixed incorporation with Ag nanoparticles and MWNTs, the sheet resistance of SnO₂ thin films decreased relative to incorporation of either single component. Valence band spectral analyses of the nano-hybridized SnO₂ thin films showed a relation between band structural change and electrical resistance. Direct-patterning of SnO₂ hybrid films with a line-width of 30 μm was successfully performed without photoresist or dry etching. These results suggest that a micro-patterned system can be simply fabricated, and the electrical properties of SnO₂ films can be improved by incorporating Ag nanoparticles and MWNTs.