CdS–SnO ₂ –ZnO–Doped TiO ₂ Nanocomposite: A High-Efficiency Photoanode for Dye-Sensitized Solar Cells

Abstract

The present study explores the development of a highly efficient titania-based nanocomposite for application in dye-sensitized solar cells (DSSCs). The composite incorporates zinc oxide (ZnO), tin oxide (SnO2), and cadmium sulfide (CdS)-doped titanium dioxide (TiO2), synthesized via the precipitation method. These materials are employed individually, as binary mixtures and in ternary form within DSSC architectures. Among these, the CdS–SnO2–ZnO-doped TiO2 nanocomposite demonstrated notable enhancement in the photoelectric performance of DSSCs. The nanocomposite was deposited onto fluorine-doped tin oxide (FTO) glass substrates by using the doctor blade technique. Comprehensive material characterization was carried out using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) to investigate the surface morphology and elemental composition. X-ray diffraction (XRD) analysis confirmed the crystalline phases of the synthesized material. Additionally, UV–vis spectroscopy and differential reflectance spectroscopy were employed to identify the optical absorption region and to calculate the energy bandgap (Eg) using the Tauc plot, which yielded a value of 2.6 eV for the composite. Photovoltaic performance, assessed through current–voltage (I–V) measurements, revealed that the CdS–SnO2–ZnO-doped TiO2 photoanode significantly improves charge transport in DSSCs. The device demonstrated a power conversion efficiency (PCE) of 10.7% with the fluorescent dye, which is approximately four times higher than that achieved with pristine TiO2 using the same dye (2.7%).