title: Effect of TiO₂ microbead pore size on the performance of DSSCs with a cobalt based electrolyte.
abstract: Mesoporous TiO2 microbeads with well-defined intra-bead pore sizes (14 nm, 23 nm or 33 nm) were employed to investigate the effect of pore size on the performance of dye-sensitized solar cells constructed with an organic dye (MK2) and a [Co(bpy)3](2+/3+) (bpy = 2,2'-bipyridine)-based electrolyte. The TiCl4 post treatment and film thickness were optimized for the TiO2 electrodes made from beads with 33 nm intra-bead pores, and an overall energy conversion efficiency of 8.5% was achieved for a device with a 6.5 μm thick TiO2 film treated with a 20 mM TiCl4 solution. Although beads with larger pores had a smaller specific surface area, devices derived from these beads produced better photovoltaic performance. This is attributed to the improved diffusion of cobalt species inside the working electrode, as evidenced by a higher electron lifetime and dye regeneration rate recorded on these solar cells.
authors.affiliation: Department of Materials Engineering, Monash University, Melbourne, Victoria 3800, Australia. fuzhi.huang@monash.edu yibing.cheng@monash.edu.
authors.forename: Yang
authors.initials: Y
authors.lastname: Chen
authors.forename: Fuzhi
authors.initials: F
authors.lastname: Huang
authors.forename: Wanchun
authors.initials: W
authors.lastname: Xiang
authors.forename: Dehong
authors.initials: D
authors.lastname: Chen
authors.forename: Lu
authors.initials: L
authors.lastname: Cao
authors.forename: Leone
authors.initials: L
authors.lastname: Spiccia
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Caruso
authors.forename: Yi-Bing
authors.initials: YB
authors.lastname: Cheng