取向生长TiO2纳米薄膜的表面设计及气敏特性研究

项目名称： 取向生长TiO2纳米薄膜的表面设计及气敏特性研究

项目编号： No.11274100

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 夏晓红

作者单位： 湖北大学

项目金额： 95万元

中文摘要： 氧化物半导体表面与氢气相互作用机理的揭示及其表面修饰导致电子结构改变的深入理解是开发新型高效低成本氢敏器件的根本出发点。针对目前TiO2薄膜氢敏器件表面与氢气相互作用机理不清和气敏效果不够好的问题，本项目在前期自组装取向生长TiO2纳米薄膜氢敏特性的研究基础上，提出采用籽晶层诱导调控取向TiO2纳米阵列薄膜的活性表面面积，并对薄膜进行表面修饰以进一步改善其氢敏特性。结合理论设计和实验验证研究不同修饰方法导致薄膜氢敏特性改善的作用机理：（1）研究Li离子和F离子在TiO2活性表面的嵌入方式对其表面吸氢和导电性的影响；（2）研究金纳米颗粒的表面修饰在TiO2表面氢敏反应中的催化机制；（3）研究多铁纳米颗粒的自发极化和异质结的晶格匹配度对界面电子传输的影响。表面修饰改善TiO2氢敏特性机理的阐明对基于该机理的新型高效、稳定、长寿氢敏器件的研发和推广应用有重要科学意义。

中文关键词： LiF表面修饰；籽晶层诱导生长；金属纳米颗粒；BaSrTiO3纳米粉末；理论计算

英文摘要： Hydrogen sensors are of increasing importance in connection with the development and expanded use of hydrogen gas as an energy source and as a chemical reactant. Oxides-based H2 gas sensors such as SnO2, ZnO, WO3 and TiO2 are cheap,of long service life and easy to be fabricated. Dense TiO2 thin films are more stable and corrosion-resistant than other oxides. Anatase and rutile TiO2 grew along the [001] preferred orientation showed excellent H2 sensing properties in our recent work, with both having room temperature response and the sensitivity being even better under 100 C. The H2 sensor based on anatase TiO2 thin film had shorter response time, while the working temperature needed to be decreased and the sensitivity should be further improved. In this project, firstly, LiF will be incorporated onto the anatase (001) surface to help absorb H2 and to improve the surface conductance of the thin film. Li+ has very high combination energy with H2 and F- is a very effective doping element for the improvement of the electrical conductivity of oxides. DFT calculation could be adopted to calculate the change of surface energy, density of states, energetics of oxygen vacancy after the incorportation of LiF, so that the function of LiF could be clarified. Secondly, we will try to decorate the anatase (001) surface with Au

英文关键词： LiF surface decoration；seed layer induced growth；metal nanoparticles；BaSrTiO3 nanopowder；theoretical calculation