Optical transparency of ZnO thin film using localized surface plasmons of Ag nanoislands

• Plasmonic properties of Ag nanoislands inserted between ZnO layers have been studied.
• Multilayer films of ZnO and Ag are deposited using spray pyrolysis and vacuum unit.
• Multilayer films shown extremely high transmission (95%) in the range 600–900 nm.
• Experimental results are simulated using Maxwell–Garnet Theory and Transfer matrix.
• Photoluminescence spectra of ZnO and ZnO/Ag/ZnO films have also been studied.

Localized surface plasmons mediated optical transparencies of ZnO/Ag/ZnO, ZnO/Ag and Ag/ZnO have been investigated. These multilayered films have been fabricated using a combination of simple techniques like Spray Pyrolysis and Vacuum Deposition. A clear signature of localized surface plasmons has been observed in transmission spectra due to silver nanoislands. This is in contrast to other previously reported articles, which use mainly sputtering method. Key factor for this difference is the fabrication technique. Salient feature of these multilayer films is also the extremely high transmittance (near 95%) in the range 600–900 nm with transmission minima in the range 450–550 nm. Experimental results are successfully interpreted theoretically using extended Maxwell–Garnett (EMG) effective medium theory and transfer matrix method. These observed results may have potential applications in high efficiency silicon solar cells.