IRES Track 1: Self-assembled liquids and thin films for efficient photon upconversion with triplet excitons in air

该IRES的科学目标是更好地理解空气稳定的光子上转换薄膜或液体的制造，这些薄膜或液体可以在漫射阳光下有效工作，而不需要目前限制实际应用的挥发性有机溶剂。 通过在九州大学度过四到八周的时间完全沉浸在日本社会中，将提供一个体验和了解人民，传统和文化的机会。美国学生将从这次国际合作中获得的文化和科学接触将是无价的。九州大学是日本排名最高的大学之一，福冈的国际化大都市大都会欢迎外国人。这个机会预计将提高参与学生在STEM劳动力中的全球竞争力，并将提供给合格的美国学生，特别是那些在科学和工程领域代表性不足的学生，通过广泛接触加州州立大学系统，加州大学系统，以及参加专业会议的学生，例如，在这项国际合作中，每年有四名美国本科生和/或研究生参与者将在加州和日本进行基于三重态聚变的光子上转换的基础研究。具有三重态特征的分子激发态的融合是直接上转换太阳光子的唯一方法。虽然这些高光子上转换量子产率已在挥发性有机溶剂中得到证实，但由于差的三重态激子扩散，它们在薄膜中通常较低。美国学生将合成和制造液体或薄膜的半导体纳米晶体和分子发射体组织在各种主机，包括蛋白质，有机凝胶和表面活性剂，以了解和控制光生三重态激子的扩散。该项目旨在利用半导体纳米晶体在近红外波长内强烈吸收光，以解决分子三重态光敏剂的主要限制之一。混合纳米材料将被设计成通过氮烯交联化学来阻止分子发射体的自发结晶;在共价有机骨架中以长程有序增加液体或薄膜中的三重态扩散长度，并建立对氧的屏障以防止自旋猝灭，该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准。

The scientific goal of this IRES is to gain better understanding for the fabrication of air-stable, photon upconversion thin films or liquids that can operate efficiently with diffuse sunlight, without the need of volatile organic solvents that currently limit practical use in applications. Complete immersion in Japanese society by spending four to eight weeks in Kyushu University will provide an opportunity to experience and understand the people, traditions and culture. The cultural and scientific exposure that the U.S. students will obtain from this international collaboration will be invaluable. Kyushu University is one of the top-ranked universities in Japan, and the cosmopolitan metropolis of Fukuoka is welcoming to foreigners. This opportunity is expected to enhance the global competitiveness of the participating students in the STEM workforce, and will be made available to qualified U.S. students, especially those underrepresented in science and engineering, by broadly reaching out to the California State university system, the Univ. of California system, and students attending professional conferences organized for example, by the American Chemical Society and Materials Research Society.In this international collaboration, four U.S. undergraduate and/ or graduate participants per year will perform fundamental research on triplet-fusion based photon upconversion both in California and Japan. The fusion of molecular excited states with triplet character is the only method for directly upconverting photons from the sun. While these high photon upconversion quantum yields have been demonstrated in volatile organic solvents, they are generally lower in thin film due to poor triplet exciton diffusion. The U.S. students will be synthesizing and fabricating liquid or thin-films of semiconductor nanocrystals and molecular emitters organized in various hosts, including proteins, organogels and surfactants, to understand and control the diffusion of photogenerated triplet excitons. This project aims to use semiconductor nanocrystals to absorb light strongly in the near-infrared wavelengths to address one of the major limitations in molecular triplet photosensitizers. The hybrid nanomaterials will be designed to halt the spontaneous crystallization of the molecular emitter with nitrene crosslinking chemistry; increase triplet diffusion lengths in liquids or thin films with long-range order in covalent organic frameworks and establish a barrier to oxygen to prevent the quenching of spin-triplet excitons.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.