TiO 2 Nanotube Array/Monolayer Graphene Film Schottky Junction Ultraviolet Light Photodetectors

Schottky junctions made from a titanium dioxide nanotube (TiO 2 NT) array in contact with a monolayer graphene (MLG) film are fabricated and utilized for UV light detection. The TiO 2 NT array is synthesized by the anodization and the MLG through a simple chemical vapor deposition process. Photoconductive analysis shows that the fabricated Schottky junction photodetector (PD) is sensitive to UV light illumination with good stability and reproducibility. The corresponding responsivity ( R ), photoconductive gain ( G ), and detectivity ( D* ) are calculated to be 15 A W −1 , 51, and 1.5 × 10 12 cm Hz 1/2 W −1 , respectively. It is observed that the fabricated PD exhibits spectral sensitivity and a simple power‐law dependence on light intensity. Moreover, the height of the Schottky junction diode is derived to be 0.59 V by using a low temperature I–V measurement. Finally, the working mechanism of the TiO 2 NT array/MLG film Schottky junction PD is elucidated.