RII Track-4: van der Waals polaritonics for mid-infrared light emitters

中红外（mid-IR）是肉眼不可见的光谱的一部分，但对许多技术很重要，包括生化传感，气体监测，热照明和能源控制，安全和国防等。尽管有这些重要的应用，中红外的研究和开发一直受到阻碍，由于在这个波长范围内的有效光源的稀疏。该奖学金项目旨在通过将纳米级材料点（量子点）与传播的纳米级光波（极化激元）耦合来开发明亮的中红外光源。通过控制层材料中极化激元的性质，研究小组计划增强量子点发出的光的强度。PI将与德克萨斯大学奥斯汀分校（UT Austin）的研究人员合作，合成量子点极化子结构并进行中红外光学表征。该奖学金项目预计将开发有用的中红外光源，这将有利于上述广泛的应用。该项目还将扩大PI和奥本大学在红外光电子学和量子工程材料合成方面的研究能力，并建立奥本大学与包括UT Austin在内的其他机构之间的长期合作关系。该项目的主要目标是为具有技术重要性的中红外光谱范围（光波长从3到20 μ m）开发明亮且可控的光发射器。为此，PI提出将当前的量子点中红外发射器与极化激元货车德瓦尔斯（vdW）材料结合。vdW材料中的极化激元是高度受限且相对低损耗的，因此具有高光子态密度以通过增加量子点中电子的辐射复合率来增强中红外光发射。PI和他的合作者将在UT Austin使用最先进的分子束外延生长中红外半导体量子点。然后，研究小组将在量子点顶部制造vdW极化激元材料，并微调顶部表面结构，以优化进入自由空间的光发射。石墨烯和可配置的vdW异质结构将涉及实现光发射器的动态可调谐性。量子点极化激元发射器最后将通过中红外光致发光光谱来表征，以测试发光性能。该项目的成功演示将提供明亮和动态可调的中红外光源，并通过更好地理解量子点-极化子相互作用来补充光物质相互作用的现有知识。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。

The mid-infrared (mid-IR) is part of optical spectrum that is invisible to the naked eye but important for a wealth of technologies, including biochemical sensing, gas monitoring, thermal illumination and energy control, security and defense, and many others. Despite these vital applications, research and development in the mid-IR have been stymied due to the sparsity of efficient light sources in this wavelength range. This fellowship project aims to develop bright mid-IR light sources by coupling nanometer scale material dots (quantum dots) with propagating nanoscale optical waves (polaritons). By controlling the properties of the polaritons in layer materials, the research team plan to enhance the intensity of light emitted from quantum dots. The PI will collaborate with researchers at the University of Texas at Austin (UT Austin) to synthesis quantum dots-polariton structures and to perform the mid-IR optical characterizations. This fellowship project is expected to develop useful mid-IR light sources that will benefit a broad range of applications listed above. The project will also broaden the research capabilities of the PI and Auburn University in IR optoelectronics and quantum-engineered material synthesis, as well as establish long-term collaborations between Auburn University and other institutions including UT Austin.The primary goal of the project is to develop bright and controllable light emitters for the technically important mid-IR spectra range where light wavelength spans from 3 to 20 m. For this purpose, the PI proposes to incorporate current quantum dots mid-IR emitters with polaritonic van der Waals (vdW) materials. Polaritons in vdW materials are highly confined and relatively low-lossy, therefore possess high photonic density of states to enhance the mid-IR light emission by increasing the radiative recombination rate of electrons in quantum dots. The PI and his collaborators will grow mid-IR semiconductor quantum dots using the state-of-the-art molecular beam epitaxy at UT Austin. The research team will then fabricate vdW polaritonic materials on top of the quantum dots and fine tune the top surface structure to optimize light emission into the free space. Graphene and configurable vdW heterostructures will be involved to implement dynamic tunability for the light emitters. The quantum dot-polariton emitters will finally be characterized by mid-IR photoluminescence spectroscopy to test the light emission performance. The successful demonstration of this project will deliver bright and dynamically tunable mid-IR light sources and complement current knowledge in light-matter interactions with a better understanding of quantum dot – polariton interactions.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.