Synthesis and characterization of magnesium (Mg) doped ZnO nanomaterials with variations in growth time for DSSC applications

Abstract

This research aims to investigate the effect of growth time variation of magnesium-doped zinc oxide (ZnO:Mg) nanomaterials on the efficiency of dye-sensitized solar cells (DSSC). The synthesis method employed was the seed-mediated hydrothermal process, with a Mg doping concentration of 4% mol and growth times ranging from 9 and 10 hours. The variation of growth time was selected to analyze the relationship between the morphological evolution of ZnO:Mg nanorods and their optical properties as well as crystal structure. The samples were characterized using Ultraviolet-Visible Spectroscopy (UV-Vis) to study optical properties, X-ray Diffraction (XRD) to determine crystal structure, Field Emission Scanning Electron Microscopy (FESEM) to observe morphology, and Energy Dispersive X-ray (EDX) to identify elemental composition. The results showed that the variation of growth time affected the optical properties, crystal structure, morphology, and DSSC efficiency. The ZnO:Mg sample with an 9-hour growth time exhibited the highest absorbance of 1.45 a.u., the lowest band gap energy of 3.33 eV, and the best crystallinity with an FWHM value of 0.23° and a crystal size of 35.27 nm. FESEM analysis revealed denser and more homogeneous nanorod morphology, while EDX analysis showed the highest Mg content of 0.70% atomic percentage in the 9-hour sample.