Effect of Mn doping on the performance of ZnO-based dye-sensitized solar cells

Abstract This study investigates the effect of Mn dopant on the performance of ZnO as an electron transport layer (ETL) in dye-sensitized solar cell (DSSC) applications. The Mn concentrations in the ZnO films were varied for 0 wt% (MZ1), 0.8 wt% (MZ2), and 1.3 wt% (MZ3) through the spray pyrolysis method. As a result, X-ray diffraction (XRD) analysis revealed a reduction in ZnO crystallite size from 25 nm (MZ1) to 23 nm (MZ2) and 21 nm (MZ3). Field effect scanning electron microscopy (FESEM) showed a corresponding decrease in particle size, from 265 nm (MZ1) to 220 nm (MZ2) and 209 nm (MZ3). UV–vis absorption spectroscopy indicated a slight reduction in bandgap energy, from 3.19 eV (MZ1) to 3.15 eV (MZ3). For dye-sensitized solar cells (DSSC) application, a device structure consisting of indium tin oxide (ITO)/ZnO:Mn/dye/electrolyte/graphite was fabricated. J - V measurements demonstrated that the efficiency of DSSCs improved from 1.8% (MZ1) to 2.7% (MZ2) and 3.9% (MZ3). This study reveals the potential of Mn-doped ZnO as a cost-effective and efficient material for optimizing DSSC performance, contributing to the development of sustainable energy technologies.