Layered WO3/TiO2 nanostructures with enhanced photocurrent densities
Autor: | Kirill Sliozberg, Alan Savan, Wolfgang Schuhmann, Chinmay Khare, Alfred Ludwig, Robert Meyer |
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Rok vydání: | 2013 |
Předmět: |
Photocurrent
Nanostructure Materials science Renewable Energy Sustainability and the Environment business.industry Energy Engineering and Power Technology Sputter deposition Condensed Matter Physics Microstructure Fuel Technology Optics Sputtering Optoelectronics Charge carrier business Layer (electronics) Deposition (law) |
Zdroj: | International Journal of Hydrogen Energy. 38:15954-15964 |
ISSN: | 0360-3199 |
Popis: | Layered WO 3 /TiO 2 nanostructures, fabricated by magnetron sputtering, demonstrate significantly enhanced photocurrent densities compared to individual TiO 2 and WO 3 layers. First, a large quantity of compositions having different microstructures and thicknesses were fabricated by a combinatorial approach: diverse WO 3 microstructures were obtained by adjusting sputtering pressures and depositing the films in form of wedges; later layers of TiO 2 nanocolumns were fabricated thereon by the oblique angle deposition. The obtained photocurrent densities of individual WO 3 and TiO 2 films show thickness and microstructure dependence. Among individual WO 3 layers, porous films exhibit increased photocurrent densities as compared to the dense layer. TiO 2 nanocolumns show length-dependent characteristics, where the photocurrent increases with increasing film thickness. However, by combining a WO 3 -wedge type layer with a layer of TiO 2 nanocolumns, PEC properties strikingly improve, by about two orders of magnitude as compared to individual WO 3 layers. The highest photocurrent that is measured in the combinatorial library of porous WO 3 /TiO 2 films is as high as 0.11 mA/cm 2 . Efficient charge-separation and charge carrier transfer processes increase the photoconversion efficiency for such films. |
Databáze: | OpenAIRE |
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