Surface Plasmon Photodetector Based On Anodic Aluminum Oxide Template

As a type of photoelectric device that detects signals in a specific band,photodetectors are widely used in visible light imaging,infrared remote sensing,optical communications and other fields.The novel nano-structured surface plasmon photodetector can excite a wealth of local optical resonance modes,and has the advantages of high light absorption efficiency and adjustable absorption spectrum range.In order to achieve low-cost preparation of nanostructures and effectively control the size and distribution of nanostructures,this study used a self-made through-hole anodic aluminum oxide（AAO）template as a mask to prepare particle-type surface plasmon photodetectors.Because the structural parameters of the AAO mask determine the morphological parameters of the nanoparticles,this paper has optimized the preparation process conditions of the self-organized single-pass AAO template and the through-hole AAO template with the barrier layer removed.On this basis,the self-made through-hole AAO template was used to deposit metal nanoparticles and applied to the4H-Si C thin-film photodetector to improve the bright current of the device and broaden the response spectrum and detection spectrum.The main research results are as follows:（1）For the AAO template:by optimizing the preparation conditions of the single-pass AAO template,including oxidation time,expansion time,additive concentration,etc.,a more orderly single-pass AAO template with a period of 100 nm and a period of 500 nm was successfully prepared.Then,a polymer was used to protect the AAO template,combined with a low-cost chemical etching method,successfully prepared a through-hole AAO template with a period of 100 nm,a pore size of about 75 nm,and a period of 500 nm and a pore size of about 300 nm.（2）Particle-type surface plasmon high-performance photodetector based on the through-hole AAO template:Using the through-hole AAO template as a mask,the 4H-Si C substrate was evaporated and successfully prepared with a particle size of 300 nm and a height of 80 nm Ag nanoparticles broaden the absorption of the film from below 400 nm to the near-infrared band.Because metal nanoparticles can excite surface plasmon hot electrons,the bright current of Si C photodetectors at wavelengths of 375 nm,565 nm,660 nm,and 850nm is increased.In addition,the responsivity and detection rate of the device are improved in the visible-near infrared range.At a wavelength of 1100 nm,the responsivity and detection rate of the device increase from 2.05×10^-3 m A/W and 5.61×10⁸ Jones to 1.11×10^-1m A/W and3.02×10¹⁰ Jones,respectively.The response spectrum of the device is broadened from200-400 nm to 200-1100 nm.In summary,this paper proposes a through-hole AAO template to prepare a surface plasmon photodetector,which realizes the improvement of the bright current under violet light and broadens the response spectrum of the device to the near-infrared.This work provides reference for future research on broadening the absorption spectrum of photodetectors and improving the response rate.