Hao Lu, et al, Sci. Rep. 2015. 5. 12765

Interface engineering through atomic layer deposition towards highly improved performance of dye-sensitized solar cells

Sci. Rep. 2015. 5. 12765

H. Lu, W. Tian, J. Guo, L. Li*

A composite photoanode comprising ultralong ZnO nanobelts and TiO₂ nanoparticles was prepared and its performance in dye-sensitizedsolarcells (DSSCs) was optimized and compared to the photoanode consisting of conventional TiO₂ nanoparticles. The ultralong ZnO nanobelts were synthesized in high yield by a facile solution approach at 90 degrees C followed by annealing at 500 degrees C. The effect of the ratio of ZnO nanobelts to TiO₂ nanoparticles on the light scattering, specific surface area, and interface recombination were investigated. An optimum amount of ZnO nanobelts enhanced the photon-conversion efficiency by 61.4% compared to that of the conventional TiO₂ nanoparticles. To further reduce the recombination rate and increase the carrier lifetime,AtomicLayerDeposition (ALD) technique was utilized to coat a continuous TiO₂ film surrounding the ZnO nanobelts and TiO₂ nanoparticles, functioning as a barrier-free access of all electrons to conductive electrodes. This ALD treatment improved the interface contact within the whole photoanode system, finally leading to significant enhancement (137%) in the conversion efficiency of DSSCs.