Materials World Network: Intermediate Band Semiconductor Materials for High Efficiency Solar Energy Conversion

该材料世界网络专注于通过II-VI-O化合物半导体的中间电子态进行高效太阳能转换，该研究由密歇根大学（美国）和马德里大学（西班牙）太阳能能源研究所的研究人员合作进行。半导体材料的带隙中的中间态提供多个光学跃迁和对应的光学吸收带。基于这些材料的太阳能电池器件提供了一个潜在的途径，以高效率使用的材料与三个定义的吸收带在一个简化的单结结构。在II-VI族化合物半导体中引入氧等电子杂质，在实现具有高辐射效率和与太阳光谱良好匹配的能量位置的光学跃迁方面显示出希望。虽然这些材料非常适合高效的太阳能转换，但需要在材料合成和光电性能的理解方面取得重大进展。本项目的主要技术目标是1）II-VI族材料中氧态的理论和实验研究，2）II-VI-O族材料中多光子光学跃迁的表征，3）通过中间电子态确定电荷载流子输运。中间能带材料的研究将直接影响光伏太阳能电池技术，其中所设计的高效率和简单的单结器件设计将降低太阳能转换的成本。该项目将通过资助国外研究、科学家交流和举办系列研讨会，为研究生教育做出贡献。该伙伴关系还将加强密歇根大学现有的教育工作，在那里，工程100课程的新生将有一个连接到一个领先的太阳能研究所作为他们的团队项目的一部分，设计和实施由太阳能供电的系统。该项目是由材料研究部（DMR）共同资助的。NSF国际科学与工程办公室（OISE）

This Materials World Network focuses on efficient solar energy conversion via intermediate electronic states in II-VI-O compound semiconductors in collaboration between researchers at The University of Michigan (US) and the Instituto de Energia Solar at the Universidad Politécnica de Madrid (Spain). Intermediate states in the bandgap of a semiconductor material provide multiple optical transitions and corresponding optical absorption bands. Solar cell devices based on these materials offer a potential route to high efficiency using a material with three defined absorption bands in a simplified one-junction structure. The introduction of oxygen isoelectronic impurities in II-VI compound semiconductors show promise in realizing optical transitions with high radiative efficiency and energetic positions well matched to the solar spectrum. While these materials are well suited for highly efficient solar energy conversion, major advances in material synthesis and the understanding of optoelectronic properties are required. The primary technical objectives of this project are 1) the theoretical and experimental study of oxygen states in II-VI materials, 2) characterization of multi-photon optical transitions in II-VI-O materials, and 3) determination of charge carrier transport in via intermediate electron states.Research on intermediate band materials will directly impact photovoltaic solar cell technology, where the projected high efficiency and simplistic single-junction device design would lower the cost of solar energy conversion. This project will contribute to the education of graduate students by funding research abroad, exchange of scientists, and the establishment of a seminar series. The partnership will also enhance existing educational efforts at the University of Michigan, where freshman in the Engineering 100 course on photovoltaics and solar-powered systems will have a connection to a leading solar energy institute as a part of their team project to design and implement a system powered by solar energy.This project is jointly funded by Division of Materials Research (DMR) and the NSF Office of International Science and Engineering (OISE).