CAREER: Enabling Light-Driven Thermodynamic Cycles

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助作为传统机械系统的替代方案，光（光子）发射和吸收的过程可用于制冷和将热量转化为电能。这是一种固态方法，可以在尺寸，成本，速度和可靠性很重要的应用中提供显着优势，例如可再生能源，固态制冷和分布式发电。虽然很有前途，但这种方法需要对光发射和吸收过程进行特殊控制，以实现高性能。该项目的目标是通过开发一种创新设备来解决这一技术差距，该设备由叉指发射器和光吸收器（IDEAL）组成，几乎消除了光子损失，从而弥合了相对于理论极限的差距。这些设备可以跨越当前机械过程的限制，使社会能够向清洁和可持续的能源系统过渡。该项目还将向底特律大都会资源不足的学校介绍光学热力学原理，并提供研讨会，揭开研究生院的神秘面纱，从而将STEM机会扩大到代表性不足的社区。随着制造业的进步，能够实现高质量的光伏材料，热光子器件高性能的关键障碍已经成为选择性吸收带隙以上光子的能力，抑制发光光子的寄生吸收，并在提高的功率密度下保持效率。这些缺点导致相对于热力学极限的显著效率损失。该项目将通过开发一种名为IDEAL的创新设备概念来解决这一差距，该概念具有交叉指型光伏吸收器和热/发光发射器。IDEAL方法的新奇在于它（1）创建了用作完美宽带反射器的对称线，以及（2）在保持效率的同时提高了功率密度。该项目将在两个模型材料系统中实现这一概念，以测试其通用性，并绘制出热性能和光电性能之间的耦合，为高性能提供设计规则。预期的结果是几乎一个数量级的减少光子损失概率相比，目前的性能在photopolyics和发光二极管，这将产生很大的收益，热光伏发电和电致发光制冷的热力学效率。IDEAL几何结构具有额外的好处，即可能实现只有近场方法才能获得的功率密度。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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2)As an alternative to conventional mechanical systems, the process of light (photon) emission and absorption can be used for refrigeration and conversion of heat into electricity. This is a solid-state approach that can offer significant advantages in applications where size, cost, speed, and reliability are important, such as renewable energy, solid-state refrigeration, and distributed power generation. Though promising, the approach requires exceptional control over light emission and absorption processes to achieve high performance. The goal of this project is to address this technological gap by developing an innovative device, consisting of Inter-Digitated Emitters and Absorbers of Light (IDEAL), that virtually eliminates photon loss and thus bridges the gap relative to theoretical limits. Such devices can leapfrog the limitations of current mechanical processes and enable a societal transition to a clean and sustainable energy system. This project will also introduce the principles of optical thermodynamics to under-resourced schools in metro Detroit and offer workshops that demystify graduate school, thus expanding STEM opportunities to under-represented communities.With advances in manufacturing enabling high-quality photovoltaic materials, the key barrier to high performance in thermo-photonic devices has become the ability to selectively absorb above-bandgap photons, suppress parasitic absorption of luminescent photons, and maintain efficiency at elevated power densities. These shortcomings have resulted in significant efficiency losses relative to thermodynamic limits. This project will address this gap by developing an innovative device concept, named IDEAL, that features interdigitated photovoltaic absorbers and thermal/luminescent emitters. The novelty of the IDEAL approach is that it (1) creates lines of symmetry that act as perfect broadband reflectors and (2) enhances the power density while preserving efficiency. The project will implement the concept in two model material systems to test its generality and map out the coupling between thermal and optoelectronic properties to provide design rules for high performance. The expected result is almost an order of magnitude reduction in photon loss probabilities compared to current performance in photovoltaics and light-emitting diodes, which will yield large gains in the thermodynamic efficiency of thermophotovoltaic power generation and electroluminescent refrigeration. The IDEAL geometry has the added benefit of potentially enabling power densities that are only accessible to near-field approaches.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.