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论文类型：期刊论文

发表时间：2014-01-01

发表刊物：RSC ADVANCES

收录刊物：SCIE、EI、Scopus

卷号：4

期号：41

页面范围：21340-21346

ISSN号：2046-2069

摘要：Hierarchical TiO2 nanorod/nanoparticle composites were successfully prepared by TiCl4 modification of vertically aligned TiO2 nanorod (NR) arrays. After the hydrolysis of TiCl4 at room temperature, TiO2 nanoparticles (NPs) were deposited on the surface of TiO2 NRs. Morphology and structure analysis demonstrated that the TiO2 NPs were distributed around the entire surface of TiO2 NRs due to the easy permeation of TiCl4 solution between the NR space. Moreover, the high concentration of TiCl4 and long reaction time are favorable for the generation of more TiO2 NPs, which correspondingly increases the surface area of the composite to a large extent. Compared with most reported TiO2-based UV photodetectors (PDs), the present TiO2 NR/NP composite-based PDs simultaneously exhibit an extremely high response and a relatively fast response speed. The maxima of responsivity and response speed, which are 1973 A W-1 and 0.47 s (rise time) and 1.02 s (decay time), respectively, are obtained from the sample of TiO2 NR/NP-0.4 M-72 h. The fast and high photoresponses are ascribed to the large surface area provided by TiO2 NPs, the well-defined electron transport pathway offered from TiO2 NRs and the homojunction formed at the interface between them. Moreover, together with the high responsivity and the relatively fast response speed, significant UV light selectivity and a very good linear relationship between a photoresponse and the UV light intensity suggest that the present UV PDs are very competitive and highly applicable in UV light detection.