摘要
制备了SnO2棒状和球状晶粒粉体的气敏元件并进行稳定性测试,初步分析了元件的老化过程和机制。棒状和球状晶粒粉体以等重量比混合的气敏材料在850℃下高温烧结能提高气敏元件的长期稳定性。采用对材料微结构敏感的复阻抗谱方法测量了试样电性能的变化,通过吸收电流曲线分析了试样的与荷电状态有关的离子电导成分。结果表明,试样在通电老化之初电阻电容值有较大波动,通电数天后趋于稳定,老化表现为晶界电阻和晶界电容的变化,说明老化过程伴随着气敏材料的晶界势垒高度和晶界耗尽层宽度的改变,其原因可能是直流偏压作用下晶界层中的离子迁移。
Gas sensors composed of Tin Oxide （ SnO2 ） nanoparticles of various aspect ratios were synthesized and their aging properties were studied by absorbing current and Complex Impedance Spectrum （CIS） methods. The results indicated that devices of optimal long - term stability could be obtained by sintering the equiponderant mixture of SnO2 nanorods and spherical nanoparticles at 850C. Using CIS method the electrical properties that are related to the microscopic structure of the samples were recorded, while the evolution of absorbing current was applied to analyze the ionic conductance that reflects the charging state of the samples. The results showed considerable fluctuation in samples＂ impedance data in the early stage of aging, which then stablized after several days. The aging process presented as the change in both grain- boundary resistance and capacitance, which indicate corresponding change in the grain- boundary- barrier height and depletion -layer thickness. We suggest the DC -field -induced migration of ions within the grain boundaries as the probable cause of the phenomenon.
出处
《功能材料与器件学报》
CAS
CSCD
北大核心
2009年第3期228-232,共5页
Journal of Functional Materials and Devices
基金
广州市科技计划项目(2007J1-C0341)
广州市属高校科技计划项目(62015)
关键词
SNO2
气敏
老化
复阻抗谱
吸收电流
SnO2
Gas - sensing
Aging characteristics
Complex impedan ce
Absorbing current
