SYNTHESIS OF Ag-DOPED ZnO NANOMATERIALS FOR DYE SENSITIZED SOLAR CELLS AND INVESTIGATION OF THE OPTIMUM Ag DOPING RATE

Abstract

Silver (Ag) doped ZnO (SZO) nanomaterials were synthesized by hydrothermal method and characterized. ZnO nanostructures were doped with 0.0%, 0.5%, 1%, 1.5mol% Ag. These obtained SZO nanomaterials were analyzed using X-ray diffraction measurement (XRD), Scanning Electron Microscopy (SEM), and Energy Dissipative X-ray spectroscopy (EDX). The structural analysis confirmed the formation of synthesized SZO samples having a hexagonal ZnO wurtzite phase. The morphology of SZO samples changed partially and the ZnO nanorod length increased somewhat as the Ag doping ratio increased. Despite this increase, it was seen that the average crystal sizes first increased and then decreased. The crystallite sizes calculated from XRD data for 0.0, 0.5, 1.0 and 1.5mol% SZO were obtained as 41, 42, 38 and 37 nm, respectively. Ag doping concentration has increased the absorbance of SZO nanomaterials increased and the transmission decreased was observed. The band gap of the 0.0%, 0.5%, 1.0% and 1.5mol% SZO nanomaterials were measured 3.19, 3.18, 3.16 and 3.19 eV, respectively. Then dye sensitized solar cells (DSSCs) were fabricated using these SZO nanomaterials, Z907dye, N719 dye and examined their photovoltaic performances. The calculated efficiencies of DSSCs fabricated using Z907 dye for 0.0%, 0.5%, 1.0% and 1.5mol% SZO were 0.005, 0.51, 0.46 and 0.22%, respectively. Then the calculated efficiencies of DSSCs fabricated using N719 dye for 0.0%, 0.5%, 1.0% and 1.5mol% SZO were 0.06, 0.17, 0.07 and 0.06%, respectively. In both works, DSSCs with ZnO film doped with 0.5mol% SZO showed the best photovoltaic performance. Consequently, these results indicated that the synthesized SZO nanomaterial for DSSCs of the optimum ratio of Ag doping is 0.5mol% clearly.