Page 190 - Multifunctional Photocatalytic Materials for Energy

176 Multifunctional Photocatalytic Materials for Energy

arrangements, which resulted in efficient light scattering and electron transport prop-
erties and larger dye loading, followed by improvement in the overall photovoltaic
performances. Seunghyun Baik et al. constructed layer-by-layer hybrid electrodes,
including self-standing TiO 2 NTs and NPs, by randomly depositing TiO 2 NPs onto
the bottom or the top of the TiO 2 NT arrays (as shown in Fig. 8.18A). These hy-
brid electrodes exhibited superior recombination characteristics and a longer electron
lifetime than nanoparticulate systems, yielding a PCE of 8.8% with J sc of 18.89 mA/
2
cm ; and the photoelectron lifetime was extended by 237.5%. In addition, Dai-Bin
Kuang et al. constructed trilayered TiO 2 photoelectrodes, including 0D NPs, 1D TiO 2
NTs, and 3D TiO 2 hierarchical microsized spheres on Ti metal substrates (as shown
in Fig. 8.18B) [84]. The hybrid electrodes demonstrated the advantages of efficient
charge collection, light harvesting, as well as high dye-loading capability, yielding
2
a PCE as high as 9.10% with J sc of 17.90 mA/cm under backside-illumination (as
shown in Fig. 8.18B).

Fig. 8.18 Hybrid structures for DSSCs: (A) schematic of NP and NT hybrid photoanodes
for DSSCs; (B) Schematic of 0D, 1D, and 3D TiO 2 nanostructured materials and (C) their
corresponding I-V curves.
A: Reprinted with permission from Q. Zheng et al., Hierarchical construction of self-standing
anodized titania nanotube arrays and nanoparticles for efficient and cost-effective front-illuminated
dye-sensitized solar cells. ACS Nano 5 (2011) 5088–5093. Copyright 2011, ACS Publications;
B: Reprinted with permission from W.Q. Wu, Y.F. Xu, H.S. Rao, C.Y. Su, D.B. Kuang, Trilayered
photoanode of TiO 2 nanoparticles on a 1D–3D nanostructured TiO 2 -grown flexible Ti substrate for
high-efficiency (9.1%) dye-sensitized solar cells with unprecedentedly high photocurrent density.
J. Phys. Chem. C 118 (2014) 16426–16432. Copyright 2011, ACS Publications.