CAREER:Harnessing Photon Upconversion Via Self-Assembled Hybrid Materials

非技术描述：阳光的丰富和持续的性质毫无疑问，太阳能电池技术将在未来的清洁能源战略中发挥关键作用。正是由于这个原因，人们正在努力改进目前只能将不到三分之一的太阳光转化为电能的太阳能电池设计。研究小组寻求通过一种新的、低成本的下一代太阳能电池来显著提高转换效率，这种电池利用了以前未利用的低能量太阳光。要实现这一目标，需要了解分子如何在太阳能电池表面组装和相互作用，光到电转换过程中的每一步展开的速度有多快，以及阻止太阳能电池材料从可用光中产生更多能量的障碍。与该项目相结合的是外展活动，通过博客和其他社交媒体，通过与研究相关的照片、视频和故事吸引在线社区。作为这项在线努力的补充，还有一个名为“询问科学家”的活动，在这个活动中，几位科学家在每月一次的艺术、音乐和娱乐节日期间与当地社区成员进行关于科学的随意对话。技术描述：光子上转换，结合两个或多个低能量光子来产生更高能量的激发态，是一种利用低能量光的有趣策略，绕过Shockley-Queisser极限，并将最大理论太阳能电池效率从33%提高到45%以上。然而，在环境太阳强度下实现有效的上转换并将此过程直接集成到太阳能电池中仍然具有挑战性。这个CAREER项目利用无机表面上的多层自组装来操纵界面上的能量和电子传递动力学，并直接利用太阳能电池的上转换。该项目还结合了电化学和光谱技术，以获得对金属氧化物界面组装中限制能量和电子转移过程的速率和效率的基本理解。在低能量的太阳照射下，在双层膜中加入新的敏化剂和受体分子是实现高效上转换的必要条件。与这项研究工作相辅相成的是一系列针对来自不同教育、社会经济和种族/民族背景的个人的外展活动。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。

Nontechnical description: The abundant and sustained nature of sunlight leaves little doubt that solar cell technology will play a pivotal role in future clean energy strategies. It is for this reason that considerable efforts are underway to improve upon current solar cell designs that can only convert less than a third of sun light into electricity. The research team seeks significantly increased conversion efficiencies through a new, low cost, next generation solar cell that utilizes previously unharnessed low energy sun light. Achieving this goal requires an understanding of how molecules assemble and interact on solar cell surfaces, how fast each step in the light-to-electricity conversion process unfolds, and the barriers preventing solar cell materials from creating more energy from available light. Integrated into the project are outreach activities that engage the online community with research-related photos, videos, and stories via blogs and other social media. Complementing this online effort is also an event called Ask a Scientist where several scientists engage local community members in casual conversations about science during a once-a-month art, music, and entertainment festival.Technical description: Photon upconversion, combining two or more low energy photons to generate a higher energy excited state, is an intriguing strategy to harness low energy light, circumvent the Shockley-Queisser limit, and increase the maximum theoretical solar cell efficiency from 33% to above 45%. However, achieving efficient upconversion under ambient solar intensities and incorporating this process directly into a solar cell remains challenging. This CAREER project utilizes multilayer self-assembly on inorganic surfaces to manipulate energy and electron transfer dynamics at an interface and directly harness upconversion in a solar cell. This project also combines electrochemical and spectroscopic techniques to gain a fundamental understanding of the rate and efficiency limiting energy and electron transfer processes in assemblies at metal oxide interfaces. The incorporation of new sensitizer and acceptor molecules into the bilayer film is necessary to achieve efficient upconversion under low energy, solar irradiation. Complementing this research effort are a number of outreach activities that target individuals from many different educational, socio-economic, and racial/ethnic backgrounds.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.