| As an important photoelectric element,photodetectors have important applications in imaging,sensing and automatic control.The requirement of functional and integration promotes photodetectors to develop by combining with the piezoelectric,thermoelectric and magnetoelectric effects.As an important functional material,metal chalcogenide semiconductor has excellent optical,electrical and mechanical properties.However,the traditional sulfide semiconductor material with piezoelectric effect has small spectrum response range.Therefore,it is urgent to develop a piezo-phototronic device with high performance and wide spectrum response.In this paper,a series of metal sulfide micro/nano materials have been synthesized by physical vapor deposition and hydrothermal method,A variety of photodetectors with wide spectral response are prepared by combining micro/nano materials with organic and inorganic semiconductor materials.In addition,combined with the piezoelectric effect of the material itself,the piezo-phototronic effect of the device has been studied systematically.(1)Piezo-phototronic effect modulated self-powered UV/visible/near-infrared photodetectors based on CdS:P3HT microwires:CdS single crystal microwire was prepared by physical vapor deposition with the metal bismuth as the catalyst and cadmium sulfide(CdS)powder as raw material.The diameter of the micro wire ranges from several hundred nanometers to a few microns,with a length of up to one minimeter.X-ray analysis shows that the microwire has a wurtzite structure.After that,the CdS microwire was placed on the flexible PS(polystyrene)substrate and combined with P3HT to fabricated a P-N junction photodiode.The electric test shows that the device has good rectifying characteristics under the dark state.Under illumination,the devices demonstrate the self powered wide spectral response from the ultraviolet(365 nm)to the near infrared(780 nm)range.By applying 0.67%tensile strains to the cadmium sulfide microwire,we find that the photocurrent increases by 230 when the[001]tip of CdS microwire contacts with P3HT.When the[001]tip of CdS microwire contacted with P3HT,the photocurrent decreases by 80%under 0.67%tensile strain.Therefore,a piezo-phototronic effect modulated self-powered UV/visible/near-infrared photodetectors based on CdS:P3HT microwires have been fabricated.(2)A novel high-performance self-powered UV-vis-NIR photodetector based on a CdS nanorod array/reduced graphene oxide film heterojunction and its piezo-phototronic regulation:CdS nanorod arrays have been synthesized by hydrothermal method with conductive FTO glass as the substrate.The mean diameter of nanorods was 250 nm,and the average length of nanorods was 700 run.By using GO(graphene oxide)dispersions as raw materials,a uniform and continuous rGO film is prepared by thermal reduction at the top of CdS nanorods in hydrogen atmosphere.After electrode collocation,we have fabricated a schottky type photodetector based on CdS and rGO.The photoelectric measurements show that the device exhibits a rapid self powered photodetection performance in the UV(365 nm)to the infrared(1450 nm)range.Especially,the UV detection performance of the device can be increased by 11%when a 4%compression strain applied to the device.(3)Broad band photodetector based on CdS microbelt and Sb2Te3 infrared electrode:A micro/nano electrode structure based on topological insulator Sb2Te3 have been fabricated by combination of vacuum evaporation,lithography and thermal annealing with bulk Sb2Te3 as raw material.The electrical test shows that the Sb2Te3 electrode has good conductivity.The N-type CdS nanobelt was prepared by using CdS powder and metal cadmium as the raw material and gold plated Si as the substrate.After combined with CdS nanobelt,a P-N junction have been prepared.In addition,by ultilizing the good infrared absorption capability of Sb2Te3,we have prepared a visible/near-infrared photodetector with topological insulator Sb2Te3 as electrode. |
PDF Full Text Request