Preparation and properties of a phthalocyanine-sensitized TiO2 nanotube array for dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) based on an ordered titanate nanotube (TNT) array were fabricated using phthalocyanine as a dye sensitizer. The ordered TNT photoanode was prepared via two steps: (1) electrosynthesis of the TiO2 nanotube array in the HF solution by the anodization method; (2) electrodeposition of 2,9,16,23-tetra-amino zinc phthalocyanine (TAZnPc) in the TiO2 nanotubes array. The morphological characteristics and structures of TAZnPc immobilized TiO2 NTs (TAZnPc/TiO2 NTs) were examined. The average pore diameter of the TNT structures was 100 nm and its average length was 500 nm. The diffuse reflection spectra (DRS) curves of TAZnPc/TiO2 NTs had a wide absorption at 550-950 nm, which may come from the TAZnPc. The photocurrent and photovoltage of the cells were measured with an active area of 0.25 cm(2) by using CHI660B electrochemical workstation in the condition of illumination (AM 1.5, 100 mW cm(-2)). The open circuit voltage (V-oc), short circuit current (J(sc)) and fill factor (FF) of the DSSC are 0.416 V, 0.115 mA cm(-2) and 0.68, respectively.