| Photodetector is the device that converts radiant energy into an electrical signal by photoelectric effect.It is an important part of the optoelectronic system.Wide-band photodetectors have important application value in multi-wavelength imaging,communication,process control and safety monitoring.At present,the detection range of the photodetector is mainly determined by the forbidden band width of the photosensitive material.However,due to the lack of a single material with a wide wavelength response,complex preparation processes are often required to combine a plurality of materials to make a photodetector with a wide detection wavelength range,which severely constrains the development of wide-band photodetectors.We propose a novel dural-plasmon photodetector device structure to reduce the dependence of the detector on the bandgap of semiconductor,and broaden the wavelength range with higher device performance.In this work,AuNPs/Graphene/AuNPs hybrid electrode was introduced in a planar silicon Schottky photodetector.Compared with single layer of gold nanoparticles,theoretical simulation results show that plasma resonance effect is significantly enhanced by the small gap between the two layers of gold nanoparticles,which are separated by a single layer of graphene.This will lead to the formation of a large number of hot electrons.And the special structure of the hybrid electrode also ensures the efficient transmission of hot electrons.The Si photodetector exhibited a broadband response ranging from UV to near-infrared light?360-1330nm?,breaking the limitation caused by the bandgap of Si?1.2 eV?.And it showed excellent high-frequency performance,of which the 3dB bandwidth is 780kHz,and response speed is about 360ns,with low noise equivalent power value(1.6×10-8 W)at zero bias.This work demonstrated the great potential of the dual plasmonic resonance couplings in optoelectronic devices and will lead to the development of advanced plasmonic devices. |
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