Ultraviolet Sensing Characteristics Of ZnO Composite Graphene/STMS

As one of the most widely used non-electric testing technologies,ultraviolet(UV)detection technology has been applied to varies of fields,such as UV communication,biological research,fire warning,missile tracking,astronomical observation and UV interference.In this paper,ZnO composite graphene is innovatively applied to optical fiber sensing technology and UV detection.Compared with the existing UV detection technology,it exhibits great characteristics such as simple preparation method,strong anti-electromagnetic interference ability and higher sensing sensitivity.The singlemode-tapered multimode-singlemode(STMS)fiber structure is proposed,which is based on the principle of evanescent field and multimode interference.And the electronic and optical properties of ZnO,graphene and ZnO composite graphene are calculated based on first principles.Theoretical analysis results prove that when ultraviolet light irradiates the ZnO composite graphene,its carrier mobility will be changed,result in the change of the refractive index.Using hydrothermal method and sol-gel method,different shapes of ZnO(flower shape,spherical shape,rod shape and sheet shape)and different shapes of ZnO composite graphene(flower shape,spherical shape,rod shape and sheet shape)by controlling the change of p H value,reaction temperature and time are successfully prepared.The prepared sensitive materials are characterized by scanning electron microscope(SEM).The proposed singlemode-multimode-singlemode(SMS)structure is processed by the fiber fusion splicer.The multimode fiber of the SMS fiber structure is tapered by the oxyhydrogen flame fusion taper method to prepare the STMS structure.Finally,the successfully prepared ZnO and ZnO composite graphene and the STMS optical fiber structure are tightly combined by the drip coating method,thereby fabricating an ultraviolet sensor head.Set up the light path of the straight-through UV sensor system,and the sensor performance in the UV radiation illuminance range of 0 n W/cm~2?4.164 n W/cm~2is measured.The results of the investigation show that the UV sensitivity of flake ZnO/STMS is improved by 2.49 times compared with the STMS structure without sensitive materials at the the temperature of 25?;compared with the flake ZnO/STMS structure,the UV sensitivity of flake ZnO composite graphene/STMS is improved by 1.20 times.The proposed all-fiber composite structure UV sensor system provides a better solution in the field of UV detection.