Dual-functional ZnO nanorod aggregates as scattering layer in the photoanode for dye-sensitized solar cells
ABSTRACT A bilayered ZnO photoanode was constructed for dye-sensitized solar cells with a high conversion efficiency of 4.0%. One layer made of ZnO nanocrystallites increases dye adsorption, and the other consisting of ZnO nanorod aggregates provides a directed electron pathway for the electron transport together with a prominent aggregation-induced light scattering.
SourceAvailable from: Hyung Jin Sung[Show abstract] [Hide abstract]
ABSTRACT: A double-layer film composed of an upper-layer of indium-doped ZnO (IZO) nanosheets and a lower-layer of IZO nanoparticles structure (designated as DL-NS,s/NP,s:IZO) has been successfully synthesized by a simple two step electrospray method and studied as the dye-sensitized solar-cell (DSSCs) electrodes with the aim of developing a cost-effective alternative fabrication method and improving the performance of ZnO-based DSSCs. The XRD patterns demonstrated that the films exhibited the hexagonal wurtzite structure with preferential orientation along the (0 0 2) crystal plane and all the peaks slightly shifted toward the larger angle side due to the indium (In) doping. The composition of the doped ZnO films was confirmed with the help of X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS) and X-ray photospectroscopy (XPS). The upper-layer made of upright-standing IZO nanosheets (NS,s:IZO) acts as scattering centers to utilize more light as well as the direct pathway for the electrons to move towards the electrodes. The lower-layer composed of nonporous IZO nanoparticles increases the dye adsorption and also allowed for the suppression of the recombination of injected electrons. It was found that the DL-NS,s/NP,s:IZO film could significantly improve the efficiency (6.9%) of DSSCs owing to its enhanced light-scattering capability as well as intrinsic components of films, the photon-to-electron transfer process of the cells and relatively high surface area. This efficiency was significantly improved over the 4.8% obtained for double light-scattering-layer with DL-NS,s/NP,s:ZnO film and was also higher than the 3.2% achieved for single-layer of NP,s-IZO film. The fabricated cells showed highly durable cell performance, even after 40 days under atmospheric conditions. The efficiency achieved for the best DSSCs in this work is the highest ever reported value for a double light-scattering-layer ZnO film-based DSSCs.RSC Advances 01/2013; 3(47):25136. DOI:10.1039/c3ra43643h · 3.71 Impact Factor
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ABSTRACT: The ability to fabricate hierarchical one-dimensional (1D) ZnO nanoarchitecture with a high degree of multifunctionalities by suitable synthetic strategies still represents a vital issue towards boosting the ultimate photoelectric conversion efficiency of organic-inorganic hybrid solar cells (HSCs). We herein synthesize a hierarchical 1D ZnO nanoarchitecture i.e. ZnO NAR/NR grown on a dual-dimension seeded layer via an all-solution chemical bath deposition process. It is found that ZnO NAR/NR nanoarchitecture can accelerate electron separation and the D205 dye uptake, and hence simultaneously maximizing the key features of photoelectrode in HSCs i.e. carrier generation and charge transport. A remarkable efficiency of 1.30% is achieved under 1 sun illumination for D205-modified hierarchical ZnO HSC fabricated with a very thin layer of ZnO NAR/NR (thickness similar to 1 mu m) and a significant improvement is evaluated with respect to a reference photoanode made from ZnO nanorods.Electrochimica Acta 11/2014; 145:116–122. DOI:10.1016/j.electacta.2014.08.077 · 4.09 Impact Factor
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ABSTRACT: Nanobean SnO2-embedded TiO2 hollow submicrospheres are presented as a scattering layer for the first time in dye-sensitized solar cells. This designed mesoporous submicrostructures allow to simultaneously promote dye adsorption, light harvesting, and electron transport, leading to 28% improvement in the conversion efficiency compared to film-based SnO2.Chemical Communications 01/2015; 51(14). DOI:10.1039/C4CC07700H · 6.72 Impact Factor