Fabrication of three-dimensionally ordered macroporous TiO₂ film and its application in quantum dots-sensitized solar cells

Abstract

Engineering of TiO photoanode is an important strategy for increasing the photovoltaic conversion efficiency of quantum dots-sensitized solar cells (QDSSCs). In this work, three-dimensional ordered macroporous (3DOM) TiO films are fabricated by the controlled infiltrating-calcination method using the close-packed polystyrene spheres colloidal crystals as templates. The as-prepared macroporous TiO films are then applied as the photoanode in colloidal CdSe QDSSCs. This structure not only facilitates the penetration of thioglycolic acid capped CdSe QDs, and thus achieving a high coverage of the internal surface with QDs sensitizer, but also exhibits a photonic band gap with tunable positions, which could enhance the light absorption. As a result, the liquid-junction QDSSCs assembled with the CdSe sensitized 3DOM TiO yields a power conversion efficiency of 3.60% under solar illumination of 100 mW cm, and this value is much higher than that of the device using nanoporous TiO photoanode (1.82%). Our results indicate that the 3DOM TiO is a promising candidate for the construction of high-efficiency QDSSCs.

Fabrication and Characterization of Angle-Independent Structurally Colored Films Based on CdS@SiO2 Nanospheres

“…SEM images show the top view of the red CdS@ SiO 2 films, where some typical hexagonal arrangement of CdS@SiO 2 NPs represents the (1 1 1) plane of the facecentered-cubic (fcc) lattice. 37,38 Because of the short-ranged ordered arrangement of CdS@SiO 2 NPs, a particular noniridescent color can be observed from the surface of the thin film. The corresponding digital photograph of the film can be seen in the upper right corner of Figure 2b.…”

“…The inset in Figure a shows the two-dimensional Fourier transform (2D-FFT) of the SEM image with a ringlike feature, indicating that the structure has a well-defined short-range order, and the aggregation is typically amorphous and isotropic. SEM images show the top view of the red CdS@SiO 2 films, where some typical hexagonal arrangement of CdS@SiO 2 NPs represents the (1 1 1) plane of the face-centered-cubic (fcc) lattice. , Because of the short-ranged ordered arrangement of CdS@SiO 2 NPs, a particular noniridescent color can be observed from the surface of the thin film. The corresponding digital photograph of the film can be seen in the upper right corner of Figure b.…”

Core–shell ZnO@TiO2 hexagonal prism heterogeneous structures as photoanodes for boosting the efficiency of quantum dot sensitized solar cells

“…Among many materials that can be covered on the ZnO surface and form core–shell heterogeneous structures, TiO 2 is a cheap, non-toxic and stable wide-band gap semiconductor material, with many excellent properties such as good stability, diverse morphologies and excellent specific surface area, which enable it to achieve fast enough electron migration in research and applications, inhibition of charge recombination and so on. 42–45 Because ZnO and TiO 2 have similar bandgap energies, their horizontal structures meet each other and easily form heterogeneous materials. 46 Moreover, the conduction band edge of ZnO is more negative than that of TiO 2 , which makes the ZnO@TiO 2 heterogeneous structure an ideal material for improving the photoelectric chemical properties.…”