Hydrothermal synthesis of nanomoss Nb2O5 films and their ultraviolet photodetection performance

Hydrothermal process is one of the most suitable and highly controlled synthesis methods for engineering or tailoring the nanostructures of metal oxide. In the present work, etching agent assisted hydrothermal process was employed to synthesis nanostructured Nb2O5. Nanomoss Nb2O5 films were successfully synthesized on niobium foil in the ammonia fluoride based solution with concentration of 0.5 and 1.65 M at 95 A degrees C for 24 h. Material analysis of the nanomoss Nb2O5 was carried out by field emission scanning electron microscopy, atomic force microscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy analysis and Ultraviolet-visible spectroscopy. The XRD characterization revealed that the nanomoss Nb2O5 only become crystalline after annealing for 60 min at 440 A degrees C. That annealing condition also contributes to the growth of hump structure on the nanomoss films. Furthermore, it was observed that the films produce low reflectance properties in the range of 2.73-26.0% at UV wavelengths, which make them a potential candidate in UV sensor applications. To fabricate the UV sensor, platinum (Pt) electrode was deposited as a contact pad. Based on the UV characterization, the UV sensor based on nanomoss Nb2O5 films exhibited good photosensitivity of 2.0 and response time in the range of 51.4-76.8 s when exposed under turn on/off of UV light (365 nm, 750 A mu W/cm(2)) at a bias voltage of 10 V.