Fabrication of CuInS2 Sensitized TiO2 Nanorod Arrays for Photovoltaic Devices

Vertically oriented single―crystalline TiO2 nanorod arrays sensitized with CuInS2 quantum dots (QDs) were synthesized directly on fluorine―doped tin oxide (FTO) substrates by two―step solvothermal method. The as―prepared nanostructure assembly was characterized by X―ray diffraction (XRD) and scanning electron microscope (SEM). The results indicated that CuInS2 QDs were uniformly covered on the surface of the single―crystalline TiO2 nanorods. Ultraviolet visible (UV―Vis) absorption spectra showed that the absorbance of the TiO/CuInS2 nanocomposite film was extended to the visible region. Under illumination of simulated AM 1.5 G (100 mW/cm2) at one sun intensity, the QD sensitized solar cells (QD―SSCs) assembled with FTO/TiO2/CuInS2 photoelectrodes exhibited an open―circuit voltage of 0.29 V and a short―circuit current density of 0.15 mA/cm2.