Length Of TiO2 Nanotubes Research Articles

Improved performance in dye-sensitized solar cells by rationally tailoring anodic TiO2 nanotube length

In this paper, highly ordered TiO2 nanotube arrays with the tube length in a very wide range between 10 and 100μm are quickly fabricated on Ti sheets by using a modified electrochemical anodization process, and incorporated into dye-sensitized solar cells having the back-illuminated device architecture. Results indicate that the as-prepared TiO2 nanotube arrays have well-defined tube geometry, with a diameter around 100nm at present conditions, and the nanotubes are in fact comprised by TiO2 nanoparticles other than single crystals. A maximum power conversion efficiency of 4.25% for the assembled DSSC can be achieved at an optimized nanotube length of 34μm, which is consistent with the simulated results reported previously. By using the techniques of electrochemical impedance microscopy and open-circuit voltage decay, it has been further demonstrated that the vertically oriented TiO2 nanotube arrays work as direct electron transport paths, reduce the electron recombination, and thus enhance the electron collection efficiency, as compared to the mesoporous film based on TiO2 nanoparticles.

Heterogeneous 3-D nanotubular arrays of CdS-TiO2: efficient collections of reflection light for enhanced photoelectric output

This paper describes heterogeneous 3-D nanotubular arrays of CdS-TiO2 fabricated by sensitizing anodized 3-D arrays of TiO2 nanotubes with CdS nanoparticles. The radial distribution of heterogeneous arrays on the circumference of Ti wire renders them capable of collecting visible light from any direction. In surroundings where reflection visible light is artificially made by a reflector, the photocurrent output of heterogeneous 3-D arrays is enhanced by ∼69% at 0 V potential (vs. Ag/AgCl) in a standard three-electrode cell. Based on quantitative measurements of photocurrent output of 3-D arrays under known irradiation intensity from two opposite directions simultaneously, the irradiation intensity of artificial reflection light in our system was determined to be ∼58 mW cm−2. By optimizing the length of TiO2 nanotubes and deposition of CdS nanoparticles, heterogeneous 3-D arrays collect direct incident light and artificial reflection light to generate a photocurrent output (normalized to the direct irradiation area) of ∼13.2 mA at 0 V potential (vs. Ag/AgCl) under 100 mW cm−2 simulated full light.

Enhanced Photovoltaic Performance of Nanostructured Hybrid Solar Cell Using Highly Oriented TiO2 Nanotubes

Highly oriented TiO2 nanotubes have been fabricated using ZnO nanorod template through liquid reactive deposition on the ITO substrates. The diameter and length of TiO2 nanotubes can be effectively controlled for the suitable use for a hybrid solar cell by varying the diameter and length of the ZnO nanorod template. A mixture of P3HT/PCBM was infiltrated into the gaps between TiO2 nanotubes to form hybrid solar cells. The open circuit voltage, short circuit current density, fill factor, and power conversion efficiency of the hybrid solar cell using highly oriented TiO2 nanotubes were 646 mV, 9.95 mA cm−2, 51.6%, and 3.32%, respectively, much higher than 1.2% of hybrid solar cell based on ZnO nanorods tested under otherwise identical conditions and significantly higher than 0.7% of the same type hybrid solar cells reported in literature. The enhancement of the power conversion efficiency could be resulted from the highly oriented TiO2 nanotubes with smaller diameter and large specific surface area for the ...