Preparation And Humidity Sensitivity Of Fe₂O₃-ZnO Composite Nanostructures

Humidity sensors play an important role in industrial production,agricultural breeding,medical equipment,environmental protection,and people's daily household appliances.In this paper,a two-step hydrothermal method was used to successfully prepare a thin-film Fe₂O₃-ZnO composite nanostructure humidity sensor directly on a glass substrate.The performance difference of the Fe₂O₃-ZnO composite nanostructured humidity sensor under time and its mechanism in humidity sensing is discussed.In this paper,through vacuum coating,magnetron sputtering,and hydrothermal growth,we successfully completed the preparation of thin-film ZnO nanorods and Fe₂O₃-ZnO composite humidity sensors directly on glass substrates.Compared with traditional thick-film devices,This preparation method is more conducive to miniaturization and integration of devices.Using SEM,EDS,XRD,XPS,PL,and other methods for phase characterization,the phase composition and micro-morphology of ZnO,Fe₂O₃-ZnO composite materials were analyzed.The humidity measurement performance of the ZnO,Fe₂O₃-ZnO composite nanostructured humidity sensor under different humidity environments was studied through a humidity measurement device built independently.The results show that the Fe₂O₃-ZnO composite nanostructured humidity sensor has a wide detection range?11-95%RH?,high responsiveness?4805?,fast response/recovery time?3.1s/2.8s?,and good repeatability Sex and minor hysteresis?0.77%?.Through the comparison of experimental data,compared with the ZnO nanorod humidity sensor without composite Fe₂O₃,the humidity response of the composite structure is improved by 3 orders of magnitude,the response time is shortened by more than 30%,and the recovery time is reduced by 1 order of magnitude,and has better repeatable characteristics And linearity.At the same time,compared with the pure Fe₂O₃ nanomaterial humidity sensor with different nanostructures in the same literature,the Fe₂O₃-ZnO composite nanostructure exhibits higher responsiveness,shorter response-recovery time,and smaller hysteresis characteristics.In this paper,based on the difference of the humidity sensor of Fe₂O₃-ZnO composite humidity sensor under different corrosion time,this paper discusses the transition of the surface conduction mechanism during the adsorption process of water molecules through the electrochemical impedance analysis method.When Fe₂O₃-ZnO composite nanostructures have a surface relative humidity of 11%,the humidity conduction mechanism is dominated by electron conduction;when the surface relative humidity increases to 65%,electron conduction and proton conduction act simultaneously,which shows mutual interaction in P-type materials.The competitive relationship appears to be mutually reinforcing in N-type materials;when the surface relative humidity increases to 95%,the conduction mechanism is mainly proton conduction.