Comparison of Trap-state Distribution and Carrier Transport in Nanotubular and Nanoparticulate TiO2 Electrodes for Dye-Sensitized Solar Cells
2010 (English)In: ChemPhysChem, ISSN 1439-4235, E-ISSN 1439-7641, Vol. 11, no 10, 2140-2145 p.Article in journal (Refereed) Published
Dye-sensitized solar cells (DSCs) with nanotubular TiO2 electrodes of varying thicknesses are compared to DSCs based on conventional nanoparticulate electrodes. Despite the higher degree of order in one-dimensional nanotubular electrodes, electron transport times and diffusion coefficients, determined under short-circuit conditions, are comparable to those of nanoparticulate electrodes. The quasi-Fermi level, however, is much lower in the nanotubes, suggesting a lower concentration of conduction band electrons. This provides evidence for a much higher diffusion coefficient for conduction band electrons in nanotubes than in nanoparticulate films. The electron lifetime and the diffusion length are significantly longer in nanotubular TiO2 electrodes than in nanoparticulate films. Nanotubular electrodes have a trap distribution that differs significantly from nanoparticulate electrodes; they possess relatively deeper traps and have a characteristic energy of the exponential distribution that is more than two times that of nanoparticulate electrodes.
Place, publisher, year, edition, pages
2010. Vol. 11, no 10, 2140-2145 p.
charge transfer, solar cells, electron lifetimes, nanotubes, trap distribution
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-135747DOI: 10.1002/cphc.201000125ISI: 000280428400016OAI: oai:DiVA.org:uu-135747DiVA: diva2:375517