|Wijeratne, K.; Akilavasan, J.; Thelakkat, M.; Bandara, J.: Enhancing the solar cell efficiency through pristine 1-dimensional SnO2 nanostructures: Comparison of charge transport and carrier lifetime of SnO2 particles vs. nanorods, Electrochimica Acta, 72, 192-198 (2012) -- DOI: 10.1016/j.electacta.2012.04.016|
Efficiency of dye-sensitized solar cells (DSSC) fabricated with pristine SnO(2) nanocrystals was reported to be less superior compared to DSSC based on mesoporous TiO(2) nanoparticles though both oxides have comparable electrical and surface properties. Owing to inherent high charge recombination properties of SnO(2) nanoparticles, photoanode fabricated with SnO(2) nanoparticles resulting in unexpected low open circuit voltage (V(oc)) and fill factor (FF). To overcome inherent charge recombination in SnO(2). we investigated pristine SnO(2) nanorods and showed enhanced V(oc), FF and overall conversion efficiency (eta) for SnO(2) nanorods. The photoanode made of SnO(2) nanorods yields nearly a 2-fold improvement in fill factor, 5 fold increases in eta and a greater than 2-fold increase in short-circuit current density with a moderate increase in open-circuit photovoltage. The effects appear to arise primarily from longer electron lifetimes and reduced charge recombination of SnO(2) nanorod based solar cells compared to that of SnO(2) particles owing to 1-D nature of SnO(2) nanorod which were evaluated by open-circuit voltage decay (OCVD) and electrochemical impedance spectroscopy (EIS) methods.