Titanium oxide decorated zinc oxide nanoparticles for dye-sensitized solar cell and heterojunction diode applications

In this study, the performance of dye-sensitized photovoltaic cells and electron charge recombination properties of p-n heterojunction diodes were enhanced by incorporating TiO2 into pristine ZnO nanoparticles. The ZnO nanomaterials were prepared using a green mediated technique, and the TiO2 deposition over ZnO nanoparticles was achieved through the sol-gel method. Structural analysis confirmed that the ZnO nanoparticles exhibited a hexagonal wurtzite structure, while the TiO2 nanoparticles displayed a hexagonal structure. Morphological analysis revealed that the ZnO particles had a spherical shape, whereas TiO2 particles formed clusters. The nanomaterials were further investigated to assess their functional, linear optical, and magnetic properties. For the p-n heterojunction analysis, n-type pure ZnO and ZnO/TiO2 nanomaterials were coated onto a p-type silicon substrate. The results demonstrated that the incorporation of TiO2 nanomaterials improved the coercivity and magnetization of the device. Moreover, the power conversion efficiency of the dye-sensitized solar cells significantly increased for the ZnO/TiO2 photoanode, indicating a reduced charge recombination. The TiO2 incorporated ZnO exhibited a higher efficiency (7.85%) compared to pristine ZnO (7.47%).