Study On Mechanical,Thermal And Electrical Properties Of One-Dimensional Micro/nanostructure PbS

At present,with the rapid development of information and Internet of Things,the industry put forward higher requirements to the detection of external light,temperature,heat,force and other environmental information.However,the current detection of environmental information is mainly reflected in the volatile real-time sensing.Without the external information excitation,the device quickly returns to the initial state.As a result,they can only be used in the environment with power.In order to further improve the real-time sensing performance of environmental sensing devices and form a definite non-volatile memory function,this paper improves the nanostructured materials to realize an integrated device with fast and highly sensitive real-time sensing and erasable non-volatile memory characteristics.PbS has a large exciton Bohr radius(18nm)and a narrow band gap(0.41ev),which makes it easy to modulate the surface and internal electron motion.Based on the controllable preparation of PbS one-dimensional micro/nano structure,the properties of giant thermal resistance effect,nonvolatile temperature storage,nonvolatile resistive storage and piezoresistive effect of PbS one-dimensional micro/nano structure were studied in this experiment,so that it can be applied to the new field of environmental information sensing and memory.The results are as follows:(1)The electrical transport characteristics of single micro/nanostructured devices at different temperatures show that the device exhibits a low resistance state(LRS)at low bias and low temperature;when the applied temperature is higher than 160℃,the resistance of the device increases significantly,and increases continuously with the temperature,showing a high resistance state(HRS);when the temperature continues to rise to about 200-220℃,the resistance of the device reaches the maximum,compared with the original LRS,the resistance switching ratio can reach 10~5,showing a giant thermal resistance effect.It is found that both ends of the current voltage(I-V)curve of the device show the same linear symmetry change,which proves that the resistance state change of the device is controlled by the volume trap inside the material.Under the synergistic effect of applied temperature and bias,the filling and discharging of volume traps at different depths in the material can be effectively controlled.A nonvolatile multi resistance state temperature memory device is constructed,which can be written by heating and erased by applied bias,and the nonvolatile memory window value can reach 10~3.This project realized the real-time sensing of temperature information with high sensitivity and the non-volatile memory function of erasure;(2)The two ends of a single micro/nano structure device are annealed asymmetrically,and we found that the device has a significant bipolar resistance switch characteristic under 3V cyclic bias.When the reading voltage is 0.1V and the writing/erasing voltage is±4V,the memory window ratio of the device reaches 1500;when the reading voltage is 0.1V and the writing/erasing voltage is±8V,the memory window ratio of the device can reach 80000,which shows the non-volatile giant resistance memory effect.A nonvolatile multi bits resistive memory device is obtained,which can be regulated by different bias,and has an excellent memory window value and erasure reliability;(3)The piezoresistive performance of the device is studied under the action of external stress.The results show that the resistance of the device decreases under the action of compressive strain,and the resistance to switch ratio reaches 40 when the deformation is 1%;the resistance of the device increases under the action of tensile strain,and the resistance to switch ratio reaches 4000 when the deformation is 0.8%,showing an excellent giant piezoresistive effect.A high sensitivity real-time stress sensing device with great response reliability and bending tolerance is realized;This paper has carried out systematic research on the controllable preparation,component construction,performance control and application of new PbS nano semiconductor materials,which provides strong technical support and promotion for the development of the new generation sensing and memory devices of information and Internet of Things.