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Ultraviolet Light Enhanced Gas Sensor Base On Quantum Dots Sensitized Porous SnO2

Posted on:2021-04-25Degree:MasterType:Thesis
Country:ChinaCandidate:J Y MiaoFull Text:PDF
GTID:2428330611955966Subject:Condensed matter physics
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Gas sensor application technology has been widely used in the detection of toxic and harmful gas,humidity and flammable and explosive gases.Semiconductor sensors are applied to scientific study as their excellent performance and mature technology.Current reports are focused on improving the performance.Theoretical and experimental experience shows that ultraviolet?UV?excitation is an effective method to enhance sensitive property,speed up the response recovery rate and reduce the work temperature of the sensor.However,many problems remain to be solved,for instance the synthesis of materials,the structure of the device and the mechanism of light excitation.This paper mainly includes the following contents:?1?The porous SnO2 was prepared by hydrothermal synthesis.By comparing the results of the two cases with and without UV-excitation,it is proved that the introduction of UV-excitation can improve the gas response of sensors and effectively speed up the response recovery rate.?2?ZnO quantum dots were prepared by water bath synthetic method.It was compounded with porous SnO2 by means of physical stirring,and gas sensing performance of the composite materials was studied under UV-excitation,which proved that UV light can enhance the response of the material.?3?The prepared TiO2 quantum dots composite with porous SnO2 were prepared by physical adsorption and the composite proportion was regulated to form evenly disperse the quantum dots.The test under UV light can establish superior performance.In this paper,the performance of UV-enhanced gas sensing materials is studied.The low power led was used as the excitation light source and SnO2 was used as the main material of the composite.ZnO quantum dots and TiO2 quantum dots with photocatalytic properties were selected as the objects of the composite.The quantum dots are adsorbed onto the porous SnO2 structure to detect the gas under the action of light excitation.This porous SnO2 structure facilitates the diffusion of light within the material,increasing its efficiency in using ultraviolet light.In addition,such a structure also provides more ways for gas diffusion,making it easier for the gas to absorb and desorption and diffusion.The analysis of the properties will provide theoretical and practical support for the development of new UV-excited gas sensors.
Keywords/Search Tags:SnO2 porous structure, ZnO quantum dots, TiO2 quantum dots, UV-enhancement, gas sensor
PDF Full Text Request
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