Single-layer graphene/titanium oxide cubic nanorods array/FTO heterojunction for sensitive ultraviolet light detection

摘要

In this study, we report on the fabrication of a sensitive ultraviolet photodetector (UVPD) by simply transferring single-layer graphene(SLG) on rutile titanium oxide cubic nanorod (TiO(2)NRs) array. The cubic TiO(2)NRs array with strong light trapping effect was grown on fluorine-doped tin oxide (FTO) glass through a hydrothermal approach. The as-assembled UVPD was very sensitive to UV light illumination, but virtually blind to white light illumination. The responsivity and specific detectivity were estimated to be 52.1 A/W and 4.3 x 10(12) Jones, respectively. What is more, in order to optimize device performance of UVPD, a wet-chemistry treatment was then employed to reduce the high concentration of defects in TiO(2)NRs during hydrothermal growth. It was found that the UVPD after treatment showed obvious decrease in sensitivity, but the response speed (rise time: 80 ms, fall time: 160 ms) and specific detectivity were substantially increased. It is also found that the speicific detectivity was imporoved by six-fold to 3.2 x 10(13) Jones, which was the best result in comparison with previously reported TiO2 nanostructures or thin film based UVPDs. This totality of this study shows that the present SLG/TiO2NR/FTO UVPD may find potential application in future optoelectronic devices and systems. (C) 2017 Elsevier B.V. All rights reserved.