Li掺杂ZnO缺陷化学性质及气敏性能研究

发布时间：2018-05-26 23:17

  本文选题：ZnO + Li掺杂　； 参考：《华中科技大学》2015年硕士论文

【摘要】：Zn O气敏传感器由于具有敏感度高、响应/恢复迅速、成本低以及长期稳定性好等优点,已广泛应用于食品生产、大气检测、医疗卫生、航空航天等领域。本研究采用实验室自主研发的气敏材料高通量筛选测试平台对Zn O及Li掺杂Zn O进行了系统的气敏性能及温阻特性研究,分析了Li掺杂对Zn O缺陷化学性质及气敏性能的影响,建立了以缺陷化学理论为基础的气敏机理模型并成功解释了Li掺杂对气敏性能的影响途径。主要工作包括:(1)分别采用均相沉淀法和水热法制备了不同Li掺杂量及不同掺杂方式的Li掺杂Zn O。通过材料微观表征手段对两种Li掺杂方式进行了表征和验证。(2)通过丝网印刷工艺将制得的Zn O气敏材料制成气敏测试元件并进行了气敏性能和温阻特性测试。测试结果表明均相沉淀法原子比x=0.1的Li掺杂Zn O具有最佳的气敏性能,在350℃下其对100 ppm的甲醛和甲醇的敏感度分别高达40.2和71.5。(3)结合缺陷化学理论对Li掺杂Zn O气敏材料的温阻特性测试结果进行了分析,解释了Zn O内部缺陷在不同温度段的行为和性质。(4)依据缺陷化学理论,建立了以氧空位和氧间隙协同作用为基础的气敏机理模型。该模型认为,在气敏响应过程中氧空位和氧间隙分别作用于氧吸附阶段和气敏响应阶段,它们的协同作用是使气敏性能提高的关键。
[Abstract]:Due to its high sensitivity, rapid response / recovery, low cost and good long-term stability, Zno gas sensor has been widely used in food production, atmospheric detection, medical and health, aerospace and other fields. The gas sensing properties and temperature resistance properties of Zn O and Li doped Zn O were systematically studied by using the high throughput screening test platform developed by the laboratory. The effects of Li doping on the chemical properties and gas sensing properties of Zn O defects were analyzed. A gas sensing mechanism model based on defect chemistry theory was established and the influence of Li doping on gas sensing performance was successfully explained. The main work includes: (1) Li-doped ZnO with different Li doping amounts and different doping modes were prepared by homogeneous precipitation method and hydrothermal method respectively. Two kinds of Li doping methods were characterized and verified by means of micro-characterization of materials. (2) the Zno gas sensing materials were made into gas sensing test elements by screen printing technology and the gas sensing properties and temperature resistance characteristics were tested. The results show that Li doped Zn _ 2O with atomic ratio of x _ (10) _ (0.1) by homogeneous precipitation method has the best gas sensitivity. At 350 鈩，

本文编号：1939351