Highly responsive UV-photodetectors based on single electrospun TiO2 nanofibres
In this work we study the optoelectronic properties of individual TiO₂ fibres produced through coupled sol-gel and electrospinning, by depositing them onto pre-patterned Ti/Au electrodes on SiO₂/Si substrates. Transport measurements in the dark give a conductivity above 2 × 10<sup>-5</sup&g...
| Autores: | , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.uam.es:10486/720309 |
| Acceso en línea: | http://hdl.handle.net/10486/720309 https://dx.doi.org/10.1039/c6tc02344d |
| Access Level: | acceso abierto |
| Palabra clave: | highly responsive UV-photodetectors single electrospun TiO₂ nanofibres optoelectronic properties of individual TiO2 fibres coupled sol–gel and electrospinning Física Química |
| Sumario: | In this work we study the optoelectronic properties of individual TiO₂ fibres produced through coupled sol-gel and electrospinning, by depositing them onto pre-patterned Ti/Au electrodes on SiO₂/Si substrates. Transport measurements in the dark give a conductivity above 2 × 10<sup>-5</sup>, which increases up to 8 × 10<sup>-5</sup> S in vacuum. Photocurrent measurements under UV-irradiation show high sensitivity (responsivity of 90 A W<sup>-1</sup> for 375 nm wavelength) and a response time to illumination of ∼5 s, which is superior to state-of-the-art TiO₂-based UV photodetectors. Both responsivity and response speed are higher in air than in vacuum, due to oxygen adsorbed on the TiO₂ surface which traps photoexcited free electrons in the conduction band, thus reducing the recombination processes. The photodetectors are sensitive to light polarization, with an anisotropy ratio of 12%. These results highlight the interesting combination of large surface area and low 1D transport resistance in electrospun TiO₂ fibres. The simplicity of the sol-gel/electrospinning synthesis method, combined with a fast response and high responsivity makes them attractive candidates for UV-photodetection in ambient conditions. We anticipate their high (photo) conductance is also relevant for photocatalysis and dye-sensitized solar cells |
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