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。鉴于资源不断减少，化石燃料价格不断上涨，全球环境因化石燃料燃烧而不断恶化，这一点具有非常高的优先地位。 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可再生和环保能源的重要候选者。可以预期，研究活动将导致新的器件结构和钙钛矿太阳能电池的性能增强。 努力把科技带到影响社会的真实的产品上。 该计划的主要部分将通过先进材料和设备以及材料表面/界面表征的跨学科研究来教育和培训研究生和本科生。该方案的一个主要重点是增加代表性不足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来纳州大学的方案，使初中和高中学生尽早接触研究。 将为高中生开发钙钛矿太阳能电池演示套件，并向整个社区展示钙钛矿太阳能电池的实用性。技术：用于高性能光电器件的有机金属三卤化物钙钛矿材料取得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。 该项目的目标是使用表面分析技术研究有机金属三卤化物钙钛矿的稳定性，解决有关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提高稳定性。 表面分析技术包括但不限于角分辨光电子能谱、紫外和X射线光电子能谱、反向光电子能谱、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、光照和器件操作的影响; 2）界面稳定性的改善，包括减少界面反应、离子迁移和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，包括中和电荷俘获缺陷和使杂质沿晶界沿着迁移最小化。该奖项反映了NSF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.