Design,Preparation And Performance Of Tellurium-Based Nanomaterials

In order to overcome the disadvantages of complex preparation,cumbersome process,high preparation cost,limited resource cost,poor film-forming property and low conductivity of nano tellurium materials.In this paper,a variety of microstructure tellurium nano films were synthesized by controlling relevant parameters in a self-built tubular furnace deposition system using simple physical vapor deposition.The experimental preparation method is simple.It is easy to control large-scale growth without catalysis and is environment-friendly.In order to improve the thermoelectric properties of nano tellurium materials,inorganic flexible nano materials(single arm carbon nanotubes SWCNTs)were introduced to composite with tellurium nano materials,so as to form Te SWCNTs composite thin films.Taking full advantage of the flexibility and high conductivity of carbon nanotubes,we can overcome the disadvantages of low conductivity of elemental tellurium and brittleness of bulk tellurium,and then combine the advantages of different materials to achieve better material properties.For Te material with many excellent physical properties,it can be sensitive to a variety of signals,including thermoelectric signal,piezoelectric signal,photoelectric signal and so on.This nano material with many excellent characteristics makes it possible for a single device to sense a variety of different physical signals,which simplifies the structure of a variety of signal sensing systems.Based on the above discussion,it is of great significance to systematically study tellurium based materials from the growth and preparation of elemental tellurium,performance regulation,material characterization and device structure design.Based on the preparation of tellurium thin film thermoelectric materials,this paper systematically studies the effects of different experimental methods and means on their thermoelectric properties and their application potential in wearable devices.1.Three kinds of tellurium nanorods,tellurium nanorollers and tellurium nanosheets polycrystalline films with different microstructures were synthesized by simple physical vapor deposition in a tubular furnace system.It was found that polycrystalline tellurium nanosheets with(l00)texture have excellent thermoelectric properties.It has high conductivity(3.49 s / cm)and Seebeck coefficient(450μ V/K)。 The reason for this is that the film texture promotes the transport of carriers in the material.2.In order to improve the thermoelectric properties of Te SWCNTs thin films,Te and carbon nanotube composite thin films were introduced.The flexible composite thin films of Te SWCNTs were successfully prepared by using SWCNTs as the deposition substrate and tellurium powder as the precursor in the tubular furnace system,and the effect of SWCNTs on the thermoelectric properties of Te nanoparticles was explored.The experimental data show that the introduction of SWCNTs improves the conductivity of the material,and the fluffy and porous SWCNTs reduces the thermal conductivity of the material.After 1000 bends,the resistance of the composite decreased by only 10%,showing the excellent composite of carbon nanotubes and tellurium nanomaterials.3.Because of the special crystal structure of Te,nano Te is also a good piezoelectric material.By setting the growth parameters,Te nanowires with(110)texture are formed,and then the sandwich nano sensor device is designed and prepared through the structural design of the device.The device enables nano tellurium to generate thermoelectric signals in the horizontal direction and piezoelectric signals in the vertical direction.The optimized device can produce an open circuit voltage of 5.5mv in the horizontal direction at a temperature difference of65 ℃.The piezoelectric signal output in the vertical direction is at the level of100 mV...