title: Effect of mesoporous TiO₂ bead diameter in working electrodes on the efficiency of dye-sensitized solar cells.
abstract: Mesoporous TiO₂ beads with diameters of 320±50, 550±50, and 830±40 nm, comprising interconnected and densely packed TiO₂ nanocrystals, were used as working electrodes for dye-sensitized solar cells (DSCs). These electrodes possess high surface areas and superior light-scattering properties, which are ideal for DSC applications. Although the electrode prepared by using 320±50 nm beads demonstrated the highest dye loading and the electrode prepared by using 550±50 nm beads showed the best light-scattering properties in the wavelength region λ=400-800 nm, DSC devices with working electrodes composed of 830±40 nm beads achieved the highest power conversion efficiencies of 9.0 % after treatment with TiCl₄. A higher electron diffusion rate (4.35×10⁻⁴ cm²  s⁻¹) and an extended electron lifetime (58 ms) were observed in DSCs composed of the largest beads, 830±40 nm, attributable to a reduced amount of inter-bead barriers and a relatively small percentage of TiO₂ nanocrystals on the surface of the beads, compared to cells containing 550±50 and 320±50 nm beads.
authors.affiliation: Department of Materials Engineering, Monash University, Wellington Road, Clayton, VIC 3800, Australia.
authors.forename: Yang
authors.initials: Y
authors.lastname: Chen
authors.forename: Fuzhi
authors.initials: F
authors.lastname: Huang
authors.forename: Dehong
authors.initials: D
authors.lastname: Chen
authors.forename: Lu
authors.initials: L
authors.lastname: Cao
authors.forename: Xiao Li
authors.initials: XL
authors.lastname: Zhang
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Caruso
authors.forename: Yi-Bing
authors.initials: YB
authors.lastname: Cheng
mesh_terms: D000327:Adsorption; D004396:Coloring Agents / Q000737:chemistry; D011211:Electric Power Supplies; D004566:Electrodes; D008027:Light; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009942:Organometallic Compounds / Q000737:chemistry; D016062:Porosity; D012542:Scattering, Radiation; D012993:Solar Energy; D013861:Thiocyanates / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004396:Coloring Agents; D009942:Organometallic Compounds; D013861:Thiocyanates; C506095:bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(II) bis(tetrabutylammonium) bis(thiocyanate); C009495:titanium dioxide; C025096:titanium tetrachloride; D014025:Titanium