稀土掺杂锆钛酸钡钙陶瓷的电调控可见-近红外发光及其光-电耦合研究

Multifunctional ceramics, containing two or more physical characteristics such as sonic, optical, magnetic, electrical, electrical and mechanical properties, are of great significance to develop novel optoelectronic devices. After introducing rare-earth ions (RE3+) in the inorganic ferroelectrics, the piezoelectricity/ferroelectricity (from the host matrix) together with the unique luminescent performance (from the RE3+) can be realized, benefitting in achieving optical-electrical coupling. Based on the RE3+-doped luminescent and ferroelectric ceramics (Ba0.7Ca0.3)TiO3-Ba(Ti0.8Zr0.2)O3 (BCTZ:RE), the motivation of our proposal is to study the microstructures and phase structures to find the morphotropic phase boundaries of the host material, and then to investigate the piezoelectric, ferroelectric and photoluminescent (PL) properties. By applying external electric field on the thin ceramic disks, we monitor the changes of PL (including up-conversion and down-conversion visible emissions, near infrared emissions) intensity by an in-situ and real-time way in order to set up a coupling mechanism among ferroelectric polarization, phase structure and PL. According to the research results, we generalize and summarize the modulation mechanism of PL performances from visible to near infrared ranges in the RE3+-doped inorganic ferroelectrics to promote the application of new luminescent and ferroelectric ceramics in the optoelectronic devices.

多功能陶瓷通常具有两种或两种以上物理特性（如声、光、磁、电、热、力），是发展新型光电子器件的重要材料。在无机铁电体中引入稀土离子后，既能保留基质材料本身的压电/铁电性能，又能赋予独特的光学性能，有利于实现光-电耦合。本项目以稀土（RE）离子掺杂发光铁电陶瓷(Ba0.7Ca0.3)TiO3-Ba(Ti0.8Zr0.2)O3 (BCTZ:RE)为核心材料，研究其微结构和相结构，确立其准同型相界（MPB），研究其压电性、铁电性和光致发光性能。通过施加外电场于薄陶瓷片，原位、实时监测上、下转换可见发光和近红外发光的变化趋势，建立铁电极化-相结构-光致发光的耦合机制。基于以上研究，对稀土无机铁电体的可见-近红外发光调控机制作理论归纳和总结，为推进新型发光铁电陶瓷材料在光电子器件中的应用奠定基础。

稀土掺杂Ba0.85Ca0.15Ti0.9Zr0.1O3 (RE-BCTZ)无铅铁电陶瓷材料是一种集铁电、压电和荧光性能于一体的多功能光电子材料。本项目基于理论计算、相结构和微观结构的研究，建立了RE-BCTZ (RE = Er和Pr)陶瓷铁电极化和光致发光的耦合机制。(1) 利用第一性原理计算Er在BCTZ晶格中的取代位置，证实Er主要取代A位，部分取代B位；当Er取代A位时，Er不再位于[TiO6]/[ZrO6]八面体晶格空隙中心，而是沿<001>方向从八面体空隙中心向上偏移，发生局部变形。(2) 研究了Er3+掺杂BCTZ陶瓷的电学和发光性能，阐述了Er3+的取代位置、样品氧空位对性能的影响机制。(3) 研究了极化和原位电场调控Er3+掺杂BCTZ和Pr3+掺杂BCTZ陶瓷的发光特性，证实陶瓷结构对称性和带隙宽度对外电场的依赖，建立电场调控陶瓷发光的内在机制，对其它体系稀土掺杂铁电体的发光调控具有重要的指导意义。本项目为推进新型发光铁电陶瓷材料在光电子器件中的应用奠定基础。