铁电/磁性半导体有序复合薄膜的光伏效应增强与多场调控

项目名称： 铁电/磁性半导体有序复合薄膜的光伏效应增强与多场调控

项目编号： No.51472113

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 万建国

作者单位： 南京大学

项目金额： 84万元

中文摘要： 铁电基薄膜的光伏效应对于发展新型太阳能电池和光电器件具有重要价值，如何提高光电流和光电转换效率是其当前应用中面临的关键问题。本项目提出大幅度增强和调控铁电基薄膜光伏效应的研究新思路：将具有磁性半导体特性的窄带隙尖晶石铁氧体引入铁电氧化物基体中，在制备相连通方式、组分和界面可控的多铁有序复合薄膜的基础上，一方面通过磁性相组分设计和磁场作用来调控其与自旋态密切相关的光学带隙和半导体特性，大幅度拓宽复合薄膜吸收太阳光的光谱范围，提升其光吸收转化效率，另外一方面通过界面磁电耦合作用和梯度应力场实现对复合体系能带结构和界面势垒的调节，进而实现对光生载流子分离和传输过程的有效调控。通过本项目实施，我们将发展出制备铁电/磁性半导体有序复合薄膜的方法，提出有效增复合薄膜光伏效应的调控途径，并阐明相应的调控规律与机制，为研发基于多铁复合薄膜、具有高效光电转换效率的新型光电池和光电器件提供研究基础。

中文关键词： 多铁材料；磁电耦合；复合薄膜；光伏效应

英文摘要： The photovoltaic effect of the ferroelectric film is important for developing new-type solar cells and photo-electric devices. For actual applications, a crucial problem on how to improve both photocurrent and power-conversion-efficiency must be resolved for the ferroelectric films. In this project, we propose a novel avenue to enhance the photovoltaic effect of the ferroelectric films. We are going to prepare the composite films by combining spinel magnetic-semiconductor ferrites with ferroelectric oxides. The composition, phase-connectivity and interface of the composite films will be controlled well. In order to improve the wide-frequency optical absorption efficiency and photonic-conversion-efficiency, we will modulate spin-relative band gap and semiconductor property by designing the compositions of magnetic phase and applying external magnetic fields. Meanwhile, we will tune the band structure and interface barrier by magnetoelectric coupling interactions at interface and graded-stress fields in the composite, consequently manipulating both the seperation and transportion of the photon-generated carriers. The aim of this project is to develop the methods for preparing some typical composite films consisting of ferroelectric oxides and magnetic semiconductors, and to propose effective avenues for enhancing the photovoltaic effect of the composite films as well as to elucidate the corresponding mudulating rules and mechanisms. Our results will become important foundations for developing new-type and high-efficiency solar cells and photo-electric devices based on multiferroicc omposite films.

英文关键词： Multiferroics;Magnetoelectric coupling;Composite films;Photovoltaic effect