碱土金属氧化物──SnO_2薄膜乙醇敏感元件的研究

Study of Alkaline Earth Metal Oxide──SnO_2 Thin Film Alcohol Sensors

采用真空镀膜、溶液浸泡、灼烧热分解方法制备了掺系列碱土金属氧化物的SnO2敏感元件．在对乙醇等七种气体的测试结果表明，掺碱土金属氧化物的SnO2元件普遍提高了对乙醇的灵敏度和选择性，而对其余气体同未掺杂元件相似，几乎不敏感．实验结果还表明，碱土金属氧化物对元件的增敏作用按MgO、CaO、SrO、BaO的顺序依次减弱．在敏感机理方面，提出了流过元件电流的公式，对元件的敏感机理作了初步探讨．

The SnO2 thin film gas sensors containing alkalinc-carth oxide MgO,CaO, SrO,and BaO have been studicd respectively, The doped SnO2 gas sensors show that improve the sensitivily to CH3 CH2OH and have low sensitivity and selectivity to C6H1, C4H10, LPG, NH3, coal gas, and H2. The improving sensitivity function of the gas sensors to CH3 CH2OH wanes in the sequence of doping matcrial: MgO, CaO, SrO, BaO. To fabricate this gas scnsor proceeds as follows: vaposing sb to substrale in vacunm for'a film; oxidizlng; immersed in alkaline-earth metal liquor for a time,and decomposing it by heating proccss. The formula of the electric current I which flows through the gas scnsors is proposed. The formula can half quantitatively explain the experimenl phenomina.