Mesoporous F-doped ZnO prism arrays with significantly enhanced photovoltaic performance for dye-sensitized solar cells

A photoanode with a mesoporous F-doped ZnO prism array (F-ZnO PA) is prepared on an F-SnO2 (FTO) glass substrate and its application in a dye-sensitized solar cell (DSSC) is investigated. A superstructure of mesoporous F-ZnO PA is obtained by thermal treatment of ZnF(OH) PA precursor, which has been previously grown directly onto the FTO substrate via chemical bath deposition. The structure and morphology of the films are characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and TEM-EDS elemental mapping. The ZnO prisms are homogenously doped by F and composed of oriented nanograins and nanopores. Owing to the higher surface area and stronger light scattering, as well as longer electron lifetime and lower charge-transfer resistance, an electrical energy conversion efficiency (η) of 3.43% is achieved for a DSSC containing a 5 μm thick mesoporous F-ZnO PA photoanode, which is much higher than that for a similar cell based on a ZnO nanorod photoanode. The knowledge acquired in this work is important for the design of efficient photoanode materials for DSSCs.

SEM image (inset: high magnification image) of the porous F-ZnO PA.Figure optionsDownload as PowerPoint slideHighlights
► Mesoporous F-doped ZnO prism array (PA) have been successfully obtained.
► This is the first report on the DSSCs that employ F-doped ZnO as the photoelectrode.
► The efficiency of F-ZnO PA based DSSC is much higher than that of ZnO nanorod DSSC.