Collaborative Research: Surface Analytical Investigation on Stability of Organometal Trihalide Perovskite

太阳能电池可以将太阳光转化为电能，提供一种清洁的可再生能源。鉴于化石燃料的资源不断减少和价格不断上涨，以及燃烧化石燃料造成的全球环境恶化，这是一个非常重要的优先事项。该项目解决了对钙钛矿太阳能电池稳定性的基本理解和改进，钙钛矿太阳能电池是一种重要的可再生和环保能源。可以预期，这些研究活动将导致钙钛矿太阳能电池的新器件结构和性能的提高。努力将科学技术转化为影响社会的实际产品。该计划的一个主要部分将是通过先进材料和器件以及材料表面/界面表征的跨学科研究来教育和培训研究生和本科生。该项目的重点是增加未被充分代表的少数民族以及各级妇女对科学研究的参与，并通过罗切斯特大学和北卡罗莱纳大学的项目向初中生和高中生提供早期研究机会。钙钛矿太阳能电池演示套件将为高中生开发，并向广大社区展示钙钛矿太阳能电池的有用性。技术方面：用于高性能光电器件的有机金属三卤化物钙钛矿材料出现了意想不到的突破和快速发展。虽然混合钙钛矿太阳能电池的功率效率在实验室中已经达到23%以上，但材料的稳定性仍然是一个关键问题。项目目标是利用表面分析技术研究有机金属三卤化物钙钛矿的稳定性，解决这些材料稳定性的基本问题和挑战，并通过材料合成和界面工程来提高其稳定性。表面分析技术包括但不限于角度分辨光电子能谱、紫外线和x射线光电子能谱、逆光发射能谱、低能电子衍射、扫描隧道显微镜、原子力显微镜和扫描电子显微镜。研究的范围和方法包括：1)不同有机金属三卤化物钙钛矿的稳定性和降解机理，包括环境因素、光照和设备操作的影响；2)界面稳定性的提高，包括减少界面反应，离子迁移，保护钙钛矿免受环境有害因素的影响；3)晶界的钝化和稳定化，包括中和电荷捕获缺陷和减少沿晶界的杂质迁移。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Solar cells can convert sunlight into electricity, providing a clean and renewable energy source. This is of very high priority given the continually diminishing resources and rising prices of fossil fuels and degrading global environment from fossil fuel burning. The project addresses fundamental understanding and improvement of the stability of perovskite solar cells, a strong candidate important for a renewable and environmentally friendly energy source. It can be expected that the research activities will result in new device structures and performance enhancements of perovskite solar cells. Efforts will be made to bring science and technology to real products that impact the society. A major part of the program will be educating and training graduate and undergraduate students through interdisciplinary research in advanced materials and devices and in materials surface/interface characterization. A strong focus of the program is on increasing participation of scientific research by under-represented minorities as well as women at all levels and providing early exposure of research to middle and high school students through programs at University of Rochester and University of North Carolina. Perovskite solar cell demonstration kits will be developed for high school students, and presentations to the community at large to show the usefulness of perovskite solar cells.Technical: There have been unexpected breakthroughs and rapid evolution in organometal trihalide perovskite materials for high-performance optoelectronic devices. Although the power efficiency of hybrid perovskite solar cells has already reached over 23% in the laboratory, the stability of the materials remains a critical issue. The goal of the project is to study the stability of organometal trihalide perovskites using surface analytical techniques, to resolve the fundamental issues and challenges regarding the stability of these materials, and to improve the stability through materials synthesis and interface engineering. The surface analytical techniques include, but are not limited to, angle-resolved photoelectron spectroscopy, ultraviolet and x-ray photoelectron spectroscopy, inverse photoemission spectroscopy, low energy electron diffraction, scanning tunneling microscopy, atomic force microscopy, and scanning electron microscopy. The scope and approaches of the research include: 1) the stability and degradation mechanisms of different organometal trihalide perovskites, including the effects of environmental factors, light illumination, and device operation; 2) the stability improvement of the interfaces, including minimizing interface reaction, ion migration, and providing protection of the perovskites from environmental detrimental factors; 3) the passivation and stabilization of grain boundaries, including neutralizing charge trapping defects and minimizing impurity migration along the grain boundaries.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.