title: Preparation of TiO₂ nanowires/nanotubes using polycarbonate membranes and their uses in dye-sensitized solar cells.
abstract: Track-etched polycarbonate (PC) membranes were used as a soft template to synthesize mesoporous TiO(2) for use in dye-sensitized solar cells (DSSCs). The Ti precursor infiltrated into the cylindrical confined spaces of PC membranes. Upon calcination at 500 °C, TiO(2) nanowires (15TNW) were obtained from PC with a 15 nm pore diameter, whereas TiO(2) nanotubes (50TNT and 100TNT) were generated from PC with 50 and 100 nm diameter pores, respectively. TNW and TNT were used as photoelectrodes in DSSCs employing a polymer electrolyte. The ranking of the cell efficiencies of the 200 nm thick TiO(2) films was 50TNT (1.1%) > 15TNW (0.8%) ≅ 100TNT (0.7%), which was mostly attributed to different amounts of dye adsorption due to different surface areas. These TNW and TNT films were further coated with the graft copolymer-directed mesoporous TiO(2) and were used as interfacial layers between the FTO glass and the 4 μm thick nanocrystalline TiO(2) film. As a result, the order of energy conversion efficiency was 15TNW (5.0%) ≅ 50TNT (4.8%) > 100TNT (4.1%). The improved performance of 15TNW was due to a higher transmittance through the electrode and a longer electron lifetime for recombination. The DSSC performance was systematically investigated in terms of interfacial resistance and charge recombination using electrochemical impedance spectroscopy.
authors: Department of Chemical and Biomolecular Engineering, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749, South Korea.
authors: Dong Kyu
authors: DK
authors: Roh
authors: Rajkumar
authors: R
authors: Patel
authors: Sung Hoon
authors: SH
authors: Ahn
authors: Dong Jun
authors: DJ
authors: Kim
authors: Jong Hak
authors: JH
authors: Kim
mesh_terms: D004396:Coloring Agents / Q000737:chemistry; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry; D008567:Membranes, Artificial; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D011076:Polycarboxylate Cement / Q000737:chemistry*; D016062:Porosity; D012993:Solar Energy; D014025:Titanium / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D004573:Electrolytes; D008567:Membranes, Artificial; D011076:Polycarboxylate Cement; C009495:titanium dioxide; C005506:polycarbonate; D014025:Titanium