Fabrication of n-TiO₂ hollow spheres monolayer-based UV detectors with different-sized nanospheres

In this paper, we report on an ultraviolet (UV) photodetector based on a pn junction structure hollow anatase n-TiO₂ nanosphere monolayer film on a p-GaN template. In order to form and transfer the well-arrayed hollow TiO₂ nanosphere monolayer film onto polydimethylsiloxane (PDMS), a facile rubbing method and polyvinyl alcohol (PVA) aqueous solution was used. To investigate the effects of different-sized hollow TiO₂ nanospheres, anatase-TiO₂ spheres of various diameters were prepared by combining template synthesis and thermal treatment. The responsiveness of the fabricated UV photodetectors using anatase n-TiO₂ monolayer/p-GaN was increased from 0.17 to 0.21 A W⁻¹ upon reducing the size of the anatase-phased hollow n-TiO₂ spheres from 660 to 360 nm. Our suggested transferable anatase-TiO₂ monolayer film is a new n-type single-layer material for electronic and optical device fields developed through the universal usage of displaceable material for targeted hetero-templates. (paper)