Design And Research Of Pyroelectric Energy Harvester Based On Plasma Effect

Pyroelectric devices have good application prospects in the field of energy harvesting due to their unique pyroelectric effects.Traditional pyroelectric solar collectors have the problem of low light absorption,which leads to low photothermal-electric conversion efficiency of the device and very small signals.In this paper,a device combining plasma effect and pyroelectric effect is designed,combining a plasma optical nano-antenna for light-induced heating with an organic pyroelectric copolymer film(P(VDF-Tr FE))together,then the temperature changes are converted into electrical signals.At the same time,the device can also be used in a temperaturevariable energy harvester to convert thermal fluctuations in the external environment into electrical signals.The specific research results of the paper are as follows:This paper uses FDTD solution software to design the structure of P(VDF-Tr FE)coupled Au nano-array,and simulates the influence of the Au nano-array structure on the absorption rate of the device.The study found that with the introduction of the Au nano-array,its plasma effect greatly improves the light absorption rate of the device.When the side length of the triangular prism of the Au nano-array is 200 nm,400nm and 600 nm respectively,the influence of the size on the absorption rate is studied,and the absorption effect is the best at 200 nm.At the same time,the simulation found that the device has a higher absorption rate for the incident light from the opposite side,which can achieve a wide angle of light absorption.On the basis of simulation,a composite structure device of P(VDF-Tr FE)and Au nanoarray with optimized process parameters was successfully developed.Different from the traditional micro-nano manufacturing lithography process,this paper uses low-cost PS beads as a mask to evaporate on ITO conductive glass to prepare regular-shaped periodic Au nanoarrays.The length of the bottom surface of the Au nano-array triangular prism prepared in the experiment is about 200 nm,which is consistent with the simulation.Afterwards,relatively flat P(VDF-Tr FE)films were prepared on ITO glass and ITO glass with Au nano-array by spin coating.As the humidity decreases,the flatness of the film is improved,and the pyroelectric coefficient reaches 4.2×10-8C/cm2 K.Through the absorption spectrum test of the composite device,it is found that the result is consistent with the simulation,which verifies the rationality of the simulation design.Finally,this paper studies the performance differences between composite structure devices(coupled gold nanoarrays)and single structure devices(uncoupled gold nanoarrays)under different wavelengths of LED light sources.Due to the coupled plasma effect,the electrical signal,capacitance accumulation,and internal temperature variation of the composite structure device are increased by four times compared with the single structure device.Under the irradiation of the 460 nm wavelength light source,the electrical signal pulse value is increased from 50 p A to 200 p A,and the response speed of the device reached 0.12 s.after that.Through the test of the unpolarized composite structure device,it is proved that the coupled gold nanoarray improves the electrical performance of the composite structure device,rather than the electrical signal gain output by the gold nanoarray itself.At the same time,the device can also realize energy harvesting from thermal fluctuations.This work has greatly improved the performance of the pyroelectric energy harvester,and at the same time saved the cost,which is conducive to the research of low-cost and high-efficiency pyroelectric energy harvester.