Research On Electrospun ZnO Micro/nano Fiber And Its Sensing Performance

ZnO nanofibers have broad application prospects in the development of nano-photoelectric sensors,photocatalytic devices and nano-generators because of their excellent properties such as wide band gap and high exciton binding energy.In order to speed up the application process of ZnO nanofibers in the field of sensor devices,the photosensitive and moisture sensitive sensor based on p-type Ce-ZnO nanofiber was prepared through electrospinning technology which has advantages of convenience,high efficience,security,and environmental protection.And the sensing mechanism was discussed and optimization to expand its application in the field of flexible wearable devices.In addiation,the application of ZnO nanofibers in the field of flexible wearable devices was expanded.Firstly,pure n-type ZnO nanofibers and p-type Ce-doped ZnO nanofibers were prepared by electrospinning followed by calcination.Their surface morphology,elemental composition,crystal structure,and opticaland electronic properties,doping concentration were characterized.Experimental results show that Ce element is incorporated into ZnO nanofibers successfully.The field-effect curve suggested that the synthesized Ce-doped ZnO nanofibers were p-type semiconductors.Both the ZnO nanofibers and the ZnO p–n homojunction had excellent UV sensibilities.The sensitivity(I_max/I₀)of the Ce-doped ZnO nanofibers was two orders higher in magnitude than that of pure ZnO nanofibers.A p–n homojunction device was prepared using the ZnO nanofibers and showed good rectifying behavior.The turn-on voltage reduced about 10 V under UV irradiation.These results suggest that Ce-doped ZnO nanofibers may have widespread applications in optical andelectronic devices.Secondly,the influence of humidity on UV photosensitivity of ZnO nanofibers is further explored.The humidity has strong influence on the UV sensing properties of ZnO-based nanofibers.In the dark,the responses of pure ZnO increased gradually with humidity increasing,while the responses of Ce-doped ZnO nanofibers decreased.When exposed to UV radiation,the response of pure ZnO nanofibers decreased with increasing humidity,while that of Ce-doped ZnO increased.And the highest responses are around88.44 and 683.67 at 97%humidity for pure ZnO and Ce-ZnO nanofibers under UV irradiation.In addition,the UV response of Ce-ZnO nanofibers is stable and repeatable.Besides,the sensing mechanism relevant to oxygen and water-related conduction was discussed briefly.These results expand the application prospects of p-type Ce-ZnO nanofibers in the field of photoelectric devices.At last,the flexible ZnO/SiO₂ hybrid nanofiber membrane was prepared via electrospinning successfully,which overcomes the problem of brittleness of ZnO.The hybrid membrane was researched to prepare a flexible pressure sensor.The study of its electrical response performance was completed.And the experimental results suggest that the flexible pressure sensor has excellent flexibility under different bending conditions.The sensitivity(I_max/I₀)of ZnO/SiO₂ hybrid nanofibers is about 12.75 when the blending curvature radius is 1.25 cm^-1.And the prepared nanofibers have excellent pressure sensibilities under various pressures.And the sensitivity(I_max/I₀)is up to 20.12 under32.60kPapressure.Inaddition,thesensorexhibitshighsensitivity,reversibility/reproducibility and good performance.The mechanisms of flexibility and pressure sensitivity are investigated.These results indicate that flexible ZnO/SiO₂ hybrid nanofiber films have a bright future in the field of flexible electronic devices.