金属氧化物半导体微纳结构制备及其气敏特性研究

发布时间：2018-03-27 04:54

本文选题：纳米材料　切入点：金属氧化物半导体　出处：《吉林大学》2015年博士论文

【摘要】：近年来，高性能的气体传感器在环境检测、工业生产以及疾病诊断等方面扮演了非常重要的角色。基于金属氧化物半导体的气体传感器因其较低的成本和优异的气敏特性成为气体传感器领域的研究热点。对于金属氧化物半导体气体传感器，优异的敏感材料是制作高性能气体传感器的基石。为了有效地检测有毒有害或易燃易爆的气体，研究人员制备了多种新颖独特的敏感材料，而开发简单、环保、低成本的合成方法一直是巨大的挑战。本论文以制作高性能气体传感器为目标，利用几种简便易操作的方法合成出多种具有独特形貌和优异气敏特性的氧化物半导体纳米材料。对所制备的氧化物半导体纳米材料进行表面修饰和成分调控来增强选择性、提高灵敏度以及响应恢复速度等。主要成果包括：（1）通过退火处理室温合成的In2S3制备出大小为10-40nm的In2O3纳米颗粒，纳米颗粒呈现轻微的团聚，室温光致发光光谱证明纳米颗粒中存在很多氧空位。大量氧空位以及较小颗粒尺寸使得In2O3纳米颗粒传感器拥有良好的丙酮气敏性能。为了避免纳米颗粒的团聚问题，合成出厚度约为10nm的表面粗糙的ZnO纳米片。薄且表面粗糙的形貌使得ZnO纳米片气体传感器对乙醇表现出好的选择性，高的灵敏度以及快的响应/恢复速度。（2）将贵金属修饰到氧化物半导体表面构建的贵金属-氧化物半导体等级结构，可增强敏感材料的表面活性，促进表面气体反应，进而提高灵敏度和选择性。因此，，利用两步易操作方法合成葵花状Ag-In2O3等级纳米结构，并研究不同的Ag修饰量对气敏性能的影响。气敏测试表明适量Ag修饰In2O3等级结构拥有更好的选择性以及更高的灵敏度，过多Ag修饰却降低了气敏性能。Ag-In2O3所表现的优异甲醛气敏特性归因于新颖的表面粗糙的葵花状等级结构和恰当修饰量的Ag纳米颗粒所引入的化学和电子作用。（3）设计、制备氧化物半导体-氧化物半导体型等级异质结构敏感材料，并应用于气体传感器，利用不同组分间的协同增感效应提升传感器的气敏特性。分别构筑了In2O3和Pd0.5Pd3O4纳米颗粒修饰的花状ZnO等级异质结构In2O3-ZnO和Pd0.5Pd3O4-ZnO。形貌和成分表征证明In2O3或Pd0.5Pd3O4纳米颗粒均匀地分散沉积在ZnO等级结构的表面。所合成的In2O3-ZnO等级异质结构气体传感器展示了增强的甲醛气敏特性，Pd0.5Pd3O4-ZnO等级异质结构传感器展现了优异的甲醇气敏特性。同时研究了纳米颗粒的修饰量对气敏性能的影响。独特的三维等级结构、恰当的纳米颗粒修饰量以及纳米颗粒与等级结构界面处的额外电子耗尽层使得等级异质结构展现优异的气敏特性。
[Abstract]:In recent years, high performance gas sensors have been detected in the environment. Industrial production and disease diagnosis play a very important role in gas sensors based on metal oxide semiconductor because of its low cost and excellent gas sensing characteristics become a hot spot in the field of gas sensors. For metal oxide semiconductor gas sensors, Excellent sensitive materials are the cornerstone of making high performance gas sensors. In order to effectively detect toxic, harmful or flammable and explosive gases, researchers have prepared a variety of novel and unique sensitive materials that are simple to develop and environmentally friendly. Low-cost synthesis methods have been a huge challenge. A variety of oxide semiconductor nanomaterials with unique morphology and excellent gas sensing properties were synthesized by using several simple and easy to operate methods. Surface modification and composition control of the prepared oxide semiconductor nanomaterials were carried out to enhance the selectivity. Improve sensitivity and response recovery speed etc. The main achievements include:. (1) In2O3 nanoparticles of 10-40nm size were prepared by annealed In2S3 synthesized at room temperature, and the nanoparticles showed slight agglomeration. Room temperature photoluminescence spectra show that there are many oxygen vacancies in the nanoparticles. A large number of oxygen vacancies and small particle size make the In2O3 nanoparticles sensor have good acetone gas sensitivity. ZnO nanocrystals with a thickness of about 10nm were synthesized, and the thin and rough surface made ZnO gas sensors exhibit good selectivity for ethanol, high sensitivity and fast response / recovery speed. (2) the noble metal modified to the surface of oxide semiconductors can enhance the surface activity of sensitive materials, promote the surface gas reaction, and then improve the sensitivity and selectivity. The sunflower Ag-In2O3 grade nanostructures were synthesized by two-step easy to operate method, and the effects of different Ag modifiers on the gas sensing properties were studied. The gas sensitivity test showed that the appropriate amount of Ag modified Ag-In2O3 grade structures had better selectivity and higher sensitivity. The excellent formaldehyde gas sensitivity of Ag-In2O3 is due to the novel sunflower grade structure with rough surface and the chemical and electronic effects introduced by the appropriately modified Ag nanoparticles. Design and manufacture of oxide semiconductor-oxide semiconductor type heterostructure sensitive materials, and their applications in gas sensors, Using the synergistic sensitization effect between different components to enhance the gas sensing characteristics of the sensor, the In2O3 and Pd0.5Pd3O4 nano-particles modified In2O3-ZnO and PD0.5Pd3O4-ZnO were constructed, respectively. The morphology and composition characterization showed that the In2O3 or Pd0.5Pd3O4 nanoparticles were homogeneous. The synthesized In2O3-ZnO grade heterostructure gas sensors exhibit enhanced formaldehyde gas sensing characteristics. Pd0.5Pd3O4-ZnO grade heterostructure sensors exhibit excellent methanol gas sensing properties. The effect of the modified amount of nanoparticles on the gas sensing performance was studied. The proper amount of nanoparticles modification and the additional electron depletion layer at the interface between the nanoparticles and the graded structure make the graded heterostructures exhibit excellent gas-sensing properties.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1

【共引文献】