Journal of Physical Chemistry A, Vol.114, No.9, 3127-3138, 2010
High-Efficiency Dye-Sensitized Solar Cells Based on the Composite Photoanocles of SnO2 Nanoparticles/ZnO Nanotetrapods
We have devised dye-sensitized solar cells (DSSCs) with >6% efficiency by employing composite photoanodes of SnO2 nanoparticles/ZnO nanotetrapods Benefiting front material advantages of both constituents, the composite photoanodes exhibit extremely large toughness factors, good charge collection, and tunable light scattering properties Among the three composite photoanodes with widely differing compositions tested. the best performance (efficiency = 6.31%) was obtained with it weight ratio of SnO2/ZnO 2-1 Mainly due to the highest saturated Jx achieved at I thinnest film thickness Charge collection losses in composite Films with more ZnO nanotetrapods content and thus necessarily larger film thicknesses appear to be a main limiting factor oil IPCE and therefore J(c). which undermines the gain from their favorable light scattering ability. An ultrathin layer of ZnO spontaneously shelled on Silo, nanoparticles is found to enhance V-alpha primarily by lifting the band edges rather than by suppressing recombination. Finally, by Intensity modulated photocurrent/pholovoltage spectroscopy (IMPS/IMVS), we have identified that recombination in SnO2/ZnO composite films is mainly determined by file ZnO shell condition oil Silo,, whereas electron transport is greatly Influenced by the morphologies and sizes of the ZnO crystalline additives In particular, ZnO nanotetrapods have proved to be superior in electron transport and therefore charge collection over ZnO particles additives in the SnO2/ZnO composite-based DSSCs.