In this study, single-crystal-like anatase TiO(2) nanowires were formed in a network structure by surfactant-assisted self-assembling processes at low temperature. The crystal lattice planes of the nanowires and networks of such wires composed of many nanoparticles were almost perfectly aligned with each other due to the "oriented attachment" mechanism, resulting in the high rate of electron transfer through the TiO(2) nanonetwork with single-crystal-like anatase nanowires. The direction of crystal growth of oriented attachment was controlled by changing the mole ratio of acetylacetone to Ti, that is, regulating both the adsorption of surfactant molecules via control of the reaction rate and the surface energy. A single-crystalline anatase exposing mainly the [101] plane has been prepared, which adsorbed ruthenium dye over 4 times higher as compared to P-25. A high light-to-electricity conversion yield of 9.3% was achieved by applying the titania nanomaterials with network structure as the titania thin film of dye-sensitized solar cells.

This work describes a procedure based on a mixed template of copolymer F127 ͓poly͑ethylene oxide͒ 106 -poly͑propylene oxide͒ 70 -poly͑ethylene oxide͒ 106 ͔ and surfactant CTAB ͑cetyltrimethylammonium bromide͒ for generating anatase TiO 2 nanocrystals. When the particle size is 3-5 nm, the surface area without aggregation is about 300 m 2 /g, but our experimental value is 180 m 2 /g. This means that not all surfaces of 3-5 nm particles are exposed. Then the prepared TiO 2 nanocrystals were used to assemble dye-sensitized very thin solar cells of about 6 m. Its photocurrent-voltage performance was investigated. The mixed template allowed the fabrication of crack-free porous TiO 2 film electrodes of various thicknesses by repetitive coating and calcinations. The transparent solar cell obtained with a six-time repetitive coating exhibited an open-circuit potential of V oc ϭ 760 mV; a short-circuit photocurrent density, J sc ϭ 17.2 mA/cm 2 ; a fill factor, f f ϭ 0.635; and an efficiency of ϭ 8.3%. A solar cell using the commercial P25 as the TiO 2 film electrode was also assembled for comparison, and the result are analyzed and discussed.

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