TiO2 nanotube structures for the enhancement of photon utilization in sensitized solar cells

Abstract

The nano-and microstructures of titanium dioxide (TiO 2 ) photoanodes in photovoltaic cells have a large impact on their photon to electron performances, including light harvesting, photogenerated electron separation, transport and recombination. This review will focus on anodic TiO 2 nanotubes (NTs) for the enhancement of photon conversion or light harvesting when incorporated in sensitized solar cells, which is valuable for increased photocurrent densities and solar cell efficiencies. By modulating the electrochemical processes which have a great impact on TiO 2 NT geometry, excellent optical properties can be achieved, resulting in the enhanced absorption of incident light and reduced light loss via reflection, penetration or transformation. The results indicate that the control of structures and morphologies of TiO 2 NTs is critical to the optimization of their applications in sensitized solar cells.

Self-organized and self-assembled TiO2 nanosheets and nanobowls on TiO2 nanocavities by electrochemical anodization and their properties

“…Also, the larger nanotubes have a similar phenomenon, however, the reflectivity decreases to 18% in the violet band. Furthermore, a considerable reduction in reflectance is observed because the absorption edge for TiO 2 -nt had a band gap energy of 3.0 eV and these results agree with other reports [36,37]. For nanocavities, the reflectance spectrum changes considerably because of interference fringes (see figure 6(a)).…”

Titania Photonic Crystals with Precise Photonic Band Gap Position via Anodizing with Voltage versus Optical Path Length Modulation

“…Among the variety of approaches to the preparation of photonic crystals (e.g., self-organization of colloidal particles [8,9] and holographic lithography [10]), the most promising method for synthesis of titanium oxide photonic crystals is the anodizing of titanium under periodic anodizing conditions [11,12,13,14,15,16,17,18]. Such an approach allows one to prepare a one-dimensional PC by varying the anodizing voltage or current density leading to the change of porosity, p , and as a result, modulation of an effective refractive index [19], n eff , throughout the film thickness.…”

Crystal Design and Photoactivity of TiO2 Nanorod Template Decorated with Nanostructured Bi2S3 Visible Light Sensitizer

“…The rod morphology helps to improve the electron injection and collection efficiency of TiO 2 semiconductor [ 1 , 2 , 3 , 4 , 5 ]. However, the wide band gap nature of TiO 2 engenders poor response to visible light [ 6 , 7 ]. In order to improve the photoactivity of TiO 2 , the strategy of semiconductor coupling is often used to enhance the solar energy conversion and utilization of TiO 2 [ 8 ].…”