Formation of photoresist-free patterned ZnO film containing nano-sized Ag by photochemical solution deposition

Direct patterning of ZnO thin film was realized without photoresist and dry etching by photochemical solution deposition. Photosensitive ortho-nitrobenzaldehyde was introduced into the solution precursors as a stabilizer and contributed to form a cross-linked network structure during photochemical reaction. Ag nanoparticles were prepared with uniform size distribution using trisodium citrate as a capping agent to incorporate into ZnO thin film in order to reduce the electrical resistance of the film. The optical and electrical properties of ZnO film with or without Ag nanoparticles after anneal at various temperatures were investigated. The reduction in transmittance with the increase in anneal temperature was observed and also the increase in the electrical resistance was found. The increase in the surface roughness of ZnO film and the decrease of surface oxygen deficiencies were mainly responsible for the decrease in transmittance and the increase in electrical resistance, respectively.