Structural Regulation And Nonlinear Optical Properties Of Lead Telluride Nanomaterials

Lead telluride(PbTe)is an important narrow band gap semiconductor in the IV-VI group.Its large thermoelectric coefficient,high refractive index,adjustable morphology,and high mobility make it highly attractive in field of optical storage,supercapacitors,electrodes,and photodetectors.However,there are few studies on the nonlinear optical properties of PbTe,especially on the structure-activity relationship between its structure and nonlinear optical properties.This research has important theoretical value and scientific significance for expanding the application of PbTe in the field of nonlinear optical limiting.In this paper,PbTe nanomaterials were prepared by microwave polyol method to effectively regulate their morphology and structure.A sol-gel wet chemistry process was used to introduce PbTe nanostructure into a silica gel glass matrix which has good physicochemical properties and transparency.The morphology,structure and linear optical properties of the substances have been characterised via scanning electron microscope,X-ray diffraction,Raman spectrum,infrared analysis spectrum,UV-visible absorption spectrum and fluorescence emission spectrum.On this basis,Z-Scan technology is used to study the nonlinear optical properties of PbTe and its composite gel glass,and to disclose the relationship between morphology and nonlinear optical properties,include its mechanism of light confinement.The main conclusions are summarized as follows:(1)Microwave polyol method can effectively control the structure of PbTe nanomaterials.The structure of PbTe hollow microspheres,PbTe block composite microspheres,and PbTe block composite hollow microspheres can be obtained by adjusting parameters such as reaction time and the amount of raw materials added.The Z-scan experimental results show that the PbTe hollow microspheres exhibit a transition from saturated absorption to reverse saturated absorption,while the PbTe block composite microspheres and their hollow structures only exhibit reverse saturated absorption,confirming that the nonlinear optical properties of PbTe nanomaterials can be regulated through structural adjustment.(2)The morphology of PbTe nanomaterials was controlled by microwave polyol method.The morphology of PbTe nanomaterials can be controlled by adjusting type and dosage of surfactants.The morphology,composition,structure,and linear optical properties of PbTe nanomaterials were systematically characterized.Z-scan experimental results show that PbTe assembled particles exhibit the strongest nonlinear optical properties and optical limiting effects among the six morphologies,and the nonlinear optical effects of PbTe nanomaterials mainly originate from free carrier absorption under single photons.It is confirmed that the optimization of nonlinear optical properties of PbTe nanomaterials can be achieved through morphology control.(3)PbTe nano material composite gel glass was successfully prepared by sol-gel method,and its morphology,structure,thermal stability and linear optical properties were systematically characterized.The Z-scan experiment results show that after the introduction of silica gel glass matrix,PbTe nanomaterials maintain their nonlinear optical properties,PbTe assembly particles still show the strongest nonlinear optical properties and optical limiting effect,and composite gel glass can maintain good nonlinear optical stability under high energy irradiation and ambient environment,which can provide the foundation for its materialization and practicality..