High efficient UV-A photodetectors based on monodispersed ligand-capped TiO2 nanocrystals and polyfluorene hybrids
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- 作者：Yangang Han ; Gang Wu ; Mang Wang ; Hongzheng Chen
- 关键词：Optical– ; electronic materials ; Polymer composite materials ; Photodetectors
- 刊名：Polymer
- 出版年：2010
- 出版时间：22 July 2010
- 年：2010
- 卷：51
- 期：16
- 页码：3736-3743
- 全文大小：1918 K
文摘
Monodispersed ligand-capped TiO2 nanocrystals are synthesized by a low temperature solvothermal method using oleic acid (OA) as the capping agent. The single layer hybrid films based on the OA-capped TiO2 nanocrystals and poly(9,9-dihexylfluorene) (PFH) are prepared by solution processing at room temperature and characterized by atomic force microscopy, UV–vis absorption and photoluminescence spectra. The hybrid film is applied in the fabrication of nanostructured UV-A photodetector (320–420 nm) by sandwiching it between two electrodes to form bulk heterojunction. The high ultraviolet signal-to-noise ratio of 3 orders of magnitude with short response time less than 200 ms can be achieved for the device. Furthermore, the device shows drastic changes in current under a wide range of UV irradiation with a linear relationship between them. The thermal behavior of the device is also discussed. The high photosensitivity in the UV-A range and the low-cost endow them with potential for environmental and biological uses.