Highly sensitive pressure switch sensors and enhanced near ultraviolet photodetectors based on 3D hybrid film of graphene sheets decorated with silver nanoparticles

Pressure switch sensors and near ultraviolet (NUV) photodetectors based on graphene nanosheets and silver nanoparticles composites were proposed and fabricated. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectra, ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared (FTIR) spectra, energy dispersive spectroscopy (EDS), field effect scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) have been employed to characterize the composites. The device based on a flexible pyramid-structured polydimethylsiloxane (PDMS) substrate was investigated as a pressure sensor, showing that the interface contact resistance can be changed sensitively by the applied pressure. In addition, benefiting from a combined effect of three-dimensional structure and enhanced light absorption of silver nanoparticles, NUV photodetectors based on the composites show a high photocurrent, a short response and recovery time of 2 ms under 365 nm NUV illumination of 0.5 mW cm−2. This work presented a simple route to obtain high performance pressure switch sensors and ultraviolet photodetectors, and would be of some benefit in device manufacture.