摘要
采用非醇盐溶胶—凝胶工艺在A l2O3基片上旋转涂敷制得掺Ag的SnO2薄膜。原子力显微镜和扫描电子显微镜分析显示:薄膜晶粒呈球形,600℃热处理粒径为20 nm左右。热处理温度升高,晶粒尺寸增大。气敏性能采用静态法测试,掺Ag薄膜对体积分数为50×10-6乙醇和汽油气体的灵敏度分别为32.7和4.9,与未掺Ag薄膜的14.4和7.2相比较,提高了乙醇气体灵敏度,抑制了汽油气体灵敏度,使选择性得到改善。直流加热条件下,试样电阻和电容在老化初期变化较大,数天后趋于稳定,复阻抗分析表明:长期稳定性与晶粒间界处电阻和电容值的变化有关,来源于晶界势垒高度和势垒宽度的变化,其本质可能是直流偏压作用下晶界层中的离子迁移。
Ag-doped SnO2 thin films are deposited on Al2O3 substrates by spin-coating using Unalcolate sol-gel synthesis. The analysis from AFM and FE-SEM micrographs indicates the crystal grains are spheric, and the size of grains is about 20 nm with 600 ℃ sintering temperature and increases with calcing temperature increasing. Gas sensitivity is tested by a static state method, The sensitivity of Ag-doped SnO2 thin films is 32.7 for volum fraction of 50 ×10^-6 alcohol vapor and is 4.9 for the same concentration gasoline vapor. The results show that Ag-doped SnO2 increases alcohol sensitivity and reduces gasoline sensitivity and improves selectivity. Under direct-current heating voltage the sample＇ s resistance and capacitance have more change early day and go to stabilize with aging time prolonged. Complex impedance analysis shows that long-term stability is relational to the change of resistance and capacitance at the grain boundary which consists in the change of height and breadth of grain boundary barrier. The change essence possible comes from the ionic transfer among grain boundary layer under direct-current biased voltage
出处
《传感器与微系统》
CSCD
北大核心
2007年第4期11-13,17,共4页
Transducer and Microsystem Technologies
基金
广东省科技计划资助项目(2002A1070304)
