Understanding and Controlling Amine-Hybrid Perovskite Vapor-Solid Reaction at Nanoscale

低成本光伏和照明技术的突破可以改变全球能源系统，减少人类活动对环境的影响。杂化卤化物钙钛矿已成为一类重要的光电材料，用于各种应用，包括太阳能收集和固态照明。本提案的目的是验证一种假设，即胺与杂化卤化物钙钛矿之间的反应具有阈值胺压力，低于该阈值胺压力，该反应可用于可靠地合成钙钛矿周围的纳米级外壳，从而提高其环境稳定性和界面电学性能。拟议的研究项目旨在发展对胺蒸气和杂化钙钛矿衬底之间反应的基本理解。一个定制的手套箱真空反应器，带有原位红外光谱，石英晶体微天平和质谱，将用于详细研究化学反应机制，并确定一系列重要的胺-钙钛矿反应的阈值压力。研究了胺的大小、质子亲和性、化学成分和加工温度对阈值压力的影响。操作条件将被确定，允许精确控制反应的程度，以可靠地生长纳米级结构。该项目将用于培养一名表面科学和纳米材料合成与表征领域最先进的实验方法的博士生。旨在整合研究和教育的拟议活动包括课程开发，将表面科学概念纳入本科和研究生课程，并为本科生提供研究机会。计划向K-12学生开展外展活动，以提高他们对表面科学、纳米技术和环境可持续性领域的认识，并鼓励学生从事STEM职业。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。

Breakthroughs in low-cost photovoltaics and lighting technologies can transform global energy systems and reduce environmental impact of human activities. Hybrid halide perovskites have emerged as an important class of optoelectronic materials for a diverse range of applications, including solar energy harvesting and solid-state lighting. The objective of this proposal is to test the hypothesis that the reaction between an amine and a hybrid halide perovskite has a threshold amine pressure, below which the reaction can be used to reliably synthesize a nanoscale shell around the perovskite, improving its environmental stability and interfacial electrical properties.The proposed research project aims to develop fundamental understanding of reactions between amine vapors and hybrid perovskite substrates. A custom-built glove box vacuum reactor with in situ infrared spectroscopy, quartz crystal microbalance, and mass spectrometry will be used to enable detailed studies of the chemical reaction mechanisms and identify the threshold pressure in a set of important amine-perovskite reactions. The effects of amine size, proton affinity, chemical composition and processing temperature on the threshold pressure will be studied. Operating conditions will be identified that allow precise control of the extent of reaction for reliable growth of nanometer-scale structures. The project will be used to train a PhD student on state-of-the-art experimental methods in the field of surface science and nanoscale materials synthesis and characterization. Proposed activities aimed at integrating research and education include curriculum development to incorporate surface science concepts into undergraduate and graduate courses and research opportunities for undergraduate students. Outreach activities to K-12 students are planned to promote awareness of the fields of surface science, nanotechnology and environmental sustainability, and to encourage students to pursue STEM careers.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.