Fabrication of peanut-like TiO2 microarchitecture with enhanced surface light trapping and high specific surface area for high-efficiency dye sensitized solar cells

Abstract

The quality of TiO2 photoelectrode is critical to fabricate high-performance dye-sensitized solar cells (DSSCs), but constructing TiO2 microstructure with high exposure reactive facets and high specific surface area is still a challenge. Herein, we present a facile route for creating a novel peanut-like (PN) anatase TiO2 microstructure with high exposed (001) facet, enhanced light trapping and large specific surface area using a one-pot hydrothermal method without fluorion assistance. With the introduction of diethylenetriamine as shape controlling agent and two-phase interface by etherification reaction of isopropyl alcohol, anatase PN TiO2 microarchitecture consisted with ultrathin nanosheets can be successfully fabricated. The obtained PN TiO2 combines the advantages of high exposed reactive (001) facets and large specific surface area (180.8 m2/g). The PN TiO2 based DSSC exhibits an outstanding photovoltaic conversion efficiency up to 9.14%, which can attribute to larger dye loading, superior light scattering capability, higher electron collection efficiency, narrower bandgap as well as efficient electron injection, together with improved electron transport and reduced charge recombination due to the unique peanut-like microstructure. Our work demonstrates the potential of PN TiO2 for improving the performance of energy storage devices.