Switch type PANI/ZnO core-shell microwire heterojunction for UV photodetection  

作　　者：Yihan Chen Longxing Su Mingming Jiang Xiaosheng Fang 

机构地区：[1]Department of Materials Science,Fudan University,Shanghai 200433,China [2]Department of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China [3]College of Science,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China

出　　处：《Journal of Materials Science & Technology》2022年第10期259-265,共7页材料科学技术（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2017YFA0204600);the National Natural Science Foundation of China(Nos.61705043,51872050 and 12061131009)。

摘　　要：In this study,single crystal ZnO microwires(MW)with size of~5.4 mm×30μm are prepared through a chemical vapor deposition technique at high temperature(1200℃).Subsequently,p-type conducting polyaniline(PANI)polymers with different conductivities are densely coated on part of the ZnO MW to construct organic/inorganic core-shell heterojunction photodetectors.The hetero-diodes reach an extremely high rectifcation ratio(I_(+3V)/I_(-3V))of 749230,and a maximum rejection ratio(I_(350nm)/I_(dark))of 3556(at-3 V),indicating great potential as rectifed switches.All the heterojunction devices exhibit strong response to ultraviolet(UV)radiation with high response speed.Moreover,the obvious photovoltaic behavior can also be obtained,allowing the device to operate as an independent and stable unit without externally supplied power.Under 0 V bias voltage,the self-powered photodetector shows a maximum responsivity of 0.56 mA W~(-1)and a rapid response speed of 0.11 ms/1.45 ms(rise time/decay time).Finally,a fnite difference time domain(FDTD)simulation is performed to further demonstrate the interaction mechanism between the incident light feld and the hexagonal cavity,which strongly supports the enhancement of the light absorption in whispering-gallery-mode resonator.

关 键 词：Core-shell structure HETEROJUNCTION High rectifcation ratio SELF-POWERED PHOTODETECTOR 

分 类 号：TN36[电子电信—物理电子学] TB34[一般工业技术—材料科学与工程]