铁酸铋基多铁薄膜的光伏效应调控及其机理研究

The research on novel photovoltaic effect of BiFeO3 multiferroic films develops a new avenue for exploiting clean and sustainable energy. Based on urgent requirements of photovoltaic industries and advantages of rich rare-earth resources in Inner Mongolia Autonomous Region, this project aims to study on the regulation of photovoltaic effect and its mechanism for the bismuth ferric based multiferroic thin films. Firstly, high-quality multiferroic films with controllable composition, good phase structure and properties will be prepared by pulse laser deposition (PLD), magnetron sputtering (MS) and sol-gel methods. Based on the so-prepared multiferroic thin films, the band-gap, ferroelectric polarization, the structure and rotation of domain walls, the interactions between domain walls, ferroelectric fatigue and photoelectric conversion efficiency can be regulated by doping modification, applying external field, optimizing electrode and modulating interface. Thus, the photovoltaic effect can be effectively regulated for the multiferroic thin films. The regulation mechanism of novel photovoltaic effect will be studied by analyzing the correlations between the multiferroic properties and the response of the photovoltaic effect. Furthermore, the physical mechanism of the photoelectric conversion for single-phase multiferroic thin films will be revealed. This project not only is of significant values in exploring frontier of anomalous ferroelectric photovoltaic effect, but also provides the important research foundation for introducing the new ferroelectric photovoltaic technology to solar cell and exploiting new energy sources.

铁酸铋多铁薄膜奇异光伏效应的研究，为发展清洁可再生能源开辟了新途径。基于内蒙古自治区光伏产业发展的迫切需求，结合自治区丰富的稀土资源优势，本项目旨在研究铁酸铋基多铁薄膜的光伏效应调控及其机理。首先，利用脉冲激光沉积、磁控溅射和溶胶-凝胶等技术制备配比可控、成相良好、性能优异的高质量铁酸铋基多铁薄膜。在此基础上，通过掺杂改性、外场作用、优化电极和调制界面等方法调控多铁薄膜的电子带隙、铁电极化、畴壁结构、畴壁翻转、畴壁相互作用、疲劳特性和光电转换效率等，进而有效调控多铁薄膜的光伏效应,并进一步研究薄膜多铁性质与光伏效应变化响应的相关性，探索多铁薄膜奇异光伏效应的调控机理，最终揭示多铁薄膜光伏效应的光电转换的物理机制。本项目的研究不仅对认识反常铁电光伏效应的物理机制具有重要的前沿探索价值，也为这项光伏新技术应用于太阳能电池、开发新能源提供重要的研究基础。

铁酸铋基多铁薄膜奇异光伏效应的研究，为发展清洁可再生能源开辟了新途径。基于内蒙古自治区光伏产业发展的迫切需求，结合自治区丰富的稀土资源优势，本项目开展了包括铁酸铋在内的铋基多铁薄膜的光伏效应调控及其机理研究。利用溶胶-凝胶等技术制备配比可控、成相良好、性能优异的高质量铋基多铁薄膜。在此基础上，通过掺杂改性、外场作用、和调制界面等方法调控多铁薄膜的光学带隙、铁电极化、畴壁结构、疲劳特性和光电转换效率等，进而有效调控多铁薄膜的光伏效应。研究发现，通过稀土钬、铈、铽、镝掺杂改性，铁酸铋薄膜获得增强的铁电性，铁电疲劳性质得到很明显改善，从而铋基铁电薄膜光伏效应可以通过稀土掺杂进行调控；通过周期性电场施加在铁电薄膜上，实现了对铁钛酸铋薄膜铁电光伏效应的有效调控；通过铁酸铋基复合薄膜的界面调控，实现了铁电薄膜的光学带隙的窄化，铁电光伏效应的光谱响应从紫外区域向可见光区移动，获得了增强的铁电光伏效应；通过过渡金属掺杂改性实现了铁酸铋薄膜、钛酸铋薄膜光学带隙的窄化，提高了其光伏性能。总之，通过铋基铁电光伏效应的稀土调控、电场调控和界面调控的深入研究揭示了多铁薄膜铁电光伏效应的调控机理。本项目的研究成果不仅对认识铁电光伏效应的物理机制具有重要的前沿探索价值，也为这项光伏新技术应用于太阳能电池、开发新能源提供重要的研究基础。