The effect of indium tin oxide nanoparticles (ITO NPs) incorporated with ZnO NPs based on structural, optical and application for flexible dye sensitized solar cells (FDSSCs)
Habtamu Fekadu Etefa, F.B. Dejene
Abstract
This study aimed to investigate the impact of zinc oxide nanoparticles (ZnO NPs) doped with indium tin oxide nanoparticles (ITO NPs) on polymer-based dye-sensitized solar cells (DSSCs). The ZnO NPs and ITO NPs were synthesized using the sol-gel and co-precipitation methods, respectively. They were then characterized and applied for dye-sensitized solar cells of a polymer-based substrate. Transmission electron microscopic (TEM) analysis revealed the presence of hexagonal structures and small spherical nanoparticles. The mean diameter of the ZnO NPs was found to be 15.22 ± 0.11 nm, while the ZnO NPs doped with ITO NPs (ZnO NPs/ITO NPs) had a mean diameter of 14.54 ± 0.16 nm. The effects of the ITO NPs on the ZnO NPs were evaluated, and it was found that these ITO NPs enhanced the performance of the flexible electrode DSSCs. After the addition of ITO NPs, the power conversion efficiency (PCE) of the ZnO NPs was boosted to be three times higher than that of the ZnO NPs DSSCs without ITO NPs. Similarly, the ultraviolet (UV) band exhibited a red shift, resulting in a lower band gap and reduced charge transfer resistance, which can enhance the PCE of the DSSCs. The polyethylene terephthalate (PET)/indium tin oxide (ITO) (PET/ITO) substrate conductive polymer showed positive outcomes for DSSCs. The PCE value for ZnO NPs was 2.198 ± 0.14 %, while for ZnO NPs/ITO NPs, it was 6.680 ± 0.12 %. This work achieved remarkable and competitive performance when compared to a solid (indium tin oxides/glass)-based substrate. • The inclusion of ITO NPs into the ZnO NPs matrix alters the morphological, electrical and optical properties of ZnO NPs. • The band gap of ZnO NPs decreases with further treatment using 10 wt% ITO NPs, indicating their combined effect on the material's electronic structure and conductivity. • XPS analysis shows that the binding energies of O 1s peaks decrease after adding ITO NPs to ZnO NPs, indicating chemical interactions between them. • PL profiles of ZnO NPs/ITO NPs show that annealing temperature influences emission peaks, with the green emission at 523 nm attributed to oxygen vacancies (Vo). • Incorporating 10 wt% ITO NPs onto ZnO NPs significantly enhances PCE of FDSSCs, improving charge separation, reducing recombination, and boosting charge transport.