Graphene on 116 faceted monocrystalline anatase nanosheet array for ultraviolet detection.

A structure composed of a nanosheet array may trap photons, which could be used to enhance the optical response via resonances; this may be highly useful in ultraviolet (UV) detection, photocatalysis, solar cells, etc. Moreover, anatase nanosheets exposed with the active {001}, {111}, and {116} facets are promising in applications such as Li-ion battery, photocatalysis, and electrochemistry. Therefore, in this study, the {116} faceted single-crystalline anatase nanosheet array with the sheet spacing in the range of several hundred nanometers was directly grown on the transparent conductive substrates. A photo-detector was fabricated by transferring a graphene electrode to the top of the anatase nanosheet array. The resultant device is inactive to visible-light irradiation and instantly responds to the UV light, which is due to the unique UV absorption property of the anatase nanosheet array and the advantage of the Schottky junction between the interfaces of graphene and anatase. The energy barrier between the two materials is 0.122 eV. We have provided a thorough research on graphene/monocrystal anatase-NSs.