Key Words:Dye-sensitized solar cells;Conversion efficiency - Dyes - Efficiency - Electron transitions - Fluorine compounds - Nanorods - Nanotubes - Open circuit voltage - Oxide minerals - Perovskite - Photosensitizers - Solar cells - Strontium titanates - Titanium dioxide - Yarn;Band-gap structures - Conductive glass - Cubic perovskite - Electron transfer - Electron-transfer resistance - External quantum efficiency - Hydrothermal reaction - TiO2 nanotube arrays
Abstract:Heterostructured SrTiO<inf>3</inf>-TiO<inf>2</inf>nanotube arrays (ST-TNTAs) on fluoride doped SnO<inf>2</inf>conductive glass (FTO) were synthesized through a three-step in-situ hydrothermal reaction. TiO<inf>2</inf>nanotubes in ST-TNTAs vertically grew on the FTO substrate in single crystallized rutile phase, while SrTiO<inf>3</inf>grains in cubic perovskite phase dispersed evenly on the surface of TiO<inf>2</inf>. The sandwich shaped all-solid-state dye-sensitized solar cells (DSSCs) were assembled with TiO<inf>2</inf>nanorods, nanotubes and ST-TNTAs as the photoanode, respectively. Once SrTiO<inf>3</inf>deposited, the position of Fermi level of the composited semiconductor raised, resulting in the increase of open circuit voltage (V<inf>OC</inf>). Meanwhile, both short-circuit current density (J<inf>SC</inf>) and photoelectrical conversion efficiency (η) increased first and then decreased with the amount of SrTiO<inf>3</inf>. In comparison to TiO<inf>2</inf>nanorods and nanotubes, ST-TNTAs demonstrated the highest photoelectrical conversion efficiency (5.42%) under the irradiation of solar simulator and external quantum efficiency (EQE) at visible region, and also the lowest electron transfer resistance, which further proved that SrTiO<inf>3</inf>acted as a good medium for electron transfer between TiO<inf>2</inf>and photosensitizer. As a result, both the increased surface area of the nanotube relative to the nanorod and the matched bandgap structure in the composited structure of TiO<inf>2</inf>and SrTiO<inf>3</inf>improve the performance of the DSSCs.<br/> © The Author(s) 2017.
Volume:165
Issue:4
Translation or Not:no