Hydrothermal growth of double-layer TiO_2 nanostructure film for quantum dot sensitized solar cells

摘要

A double-layer (DL) film with a TiO_2 nanosheet-layer on a layer of TiO_2 nanorod-array, was synthesized on a transparent conductive fluorine-doped tin oxide substrate by a two-step hydrothermal method. Starting from the precursors of NaSeSO_3, CdSO_4 and the complex of N(CH_2COOK)_3, CdSe quantum dots (QDs) were grown on the DL-TiO_2 substrate by chemical bath deposition method. The samples were characterized by X-ray diffraction, Scanning electron microscopy. Energy dispersion spectroscopy, and their optical scattering property was measured by light reflection spectrometry. Some CdSe QDs sensitized DL-TiO_2 films serve as the photoanodes, were assembled into solar cell devices and their photovoltaic performance were also charac terized. The short circuit current and open-circuit voltage of the solar cells range from 0.75 to 4.05 mA/cm~2 and 0.20 - 0.42 V under the illumination of one sun (AM1.5,100 mW/cm~2), respectively. The photocurrent density of the DL-TiO_2 film is five times higher than that of a bare TiO_2 nanorod array photoelectrode cell.