Nanostructured materials for photonics and spectroscopy

职务名称：用于光检测的尺寸减小的材料。非技术性：具有类似于石墨的分层结构的材料，每层内的原子键合牢固，但层间耦合较弱，可以很容易地分离，已成为全球密集研究的焦点。这是因为现在可以将它们的厚度减小到几层甚至单层，以创建适合于柔性基板的原子级薄的器件或透明导体。然而，它们的厚度急剧减少和新的物理特性的全部潜力尚未实现。该项目的重点是基于石墨烯，单层石墨和单层MoS 2的新型光电探测器的研究和应用。PI将通过将单层图案化为仅数十纳米宽的结构来进一步减小它们的尺寸，以创建高性能的光电探测器，这些光电探测器将在可见光范围内以及电磁频谱的其他区域工作，包括太赫兹辐射。太赫兹辐射包括微波和红外辐射之间的电磁频谱，频率范围在100 GHz和30 THz之间。由于它可以穿透大多数塑料和非导电材料，而不会产生X射线的破坏性电离效应，因此它在安全和医学成像方面具有很好的潜在应用前景。其他应用包括化学指纹识别（识别化合物）、地面短距离或卫星之间的通信，以及对景观发出的黑体辐射成像，使飞机能够在雾或烟导致能见度差的情况下着陆。 尽管太赫兹技术在许多领域都有应用潜力，但它还远未达到先进水平，因为强大的光源和灵敏的探测器还很稀缺。该项目建立在PI之前的工作基础上，证明石墨烯的纳米图案化可以产生具有非凡性能的太赫兹探测器。技术：石墨烯具有非常适合辐射热测量应用的材料特性：小的电子热容和弱的电子-声子耦合，使得入射电磁辐射很容易产生热电子。该项目将建立在PI最近的工作基础上，PI证明石墨烯量子点可以产生极高性能的THz测辐射热计。这是通过测量在石墨烯源极和漏极中形成并传播通过石墨烯量子点的热电子的电流来完成的。新的工作将把这项研究扩展到门控量子点测辐射热计，以更好地理解其非凡性能的潜在物理学。这项研究将包括其响应的频率和功率依赖性以及这些测辐射热计与天线的耦合。除了石墨烯之外，还将研究基于石墨烯和MoS 2的混合结构用于热电子测辐射热计应用。最后，本项目将研究在纳米图案化的基于MoS 2的光传感器中检测可见光辐射。

Title: Materials with reduced dimensions for light detection.Non-technical: Materials with a layered structure similar to graphite, where the atoms within each layer are strongly bonded, but the layers are weakly coupled and can be easily separated, have become the focus of intense research efforts worldwide. This is because it is now possible to reduce their thickness down to a few or even a single layer to create atomically thin devices or transparent conductors that are suitable for flexible substrates. However, the full potential of their drastic reduction in thickness and their new physical properties has not been realized. This project focuses on the study and applications of novel photodetectors based on graphene, a single layer of graphite, and single-layer MoS2. The PI will further reduce their dimensions by patterning single layers into structures that are just tens of nanometers wide, to create high-performance photodetectors that will work in the visible range, as well as in other regions of the electromagnetic spectrum, including terahertz radiation. Terahertz radiation comprises the electromagnetic spectrum between microwave and infrared radiation, in the frequency range between 100 GHz and 30 THz. Because it can penetrate through most plastics and non-conducting materials without the damaging ionization effects of x-rays, it has promising potential applications for security and medical imaging. Other applications include chemical fingerprinting (to identify chemical compounds), communication, either terrestrial short-range or between satellites, and imaging of blackbody radiation emitted by the landscape, to allow aircraft to land in conditions of poor visibility due to fog or smoke. Notwithstanding the potential for application in many fields, terahertz technology is far from advanced, because powerful sources and sensitive detectors are scarce. This project builds on previous work by the PI demonstrating that nanometer-patterning of graphene yields terahertz detectors with extraordinary performance.Technical: Graphene has material properties that are ideal for bolometric application: small electronic heat capacity and weak electron-phonon coupling, making it easy to create hot electrons with the incident electromagnetic radiation. This project will build on recent work by the PI who demonstrated that graphene quantum dots can yield extremely high-performance THz bolometers. This was done by measuring the current of hot electrons formed in the graphene source and drain electrodes and propagating through the graphene quantum dot. New work will extend the study to gated quantum dot bolometers to better understand the underlying physics of their extraordinary performance. This study will include the frequency and power dependence of their response and the coupling of these bolometers to antennas. In addition to graphene, hybrid structures based on graphene and MoS2 will also be investigated for hot-electron bolometer applications. Finally, this project will investigate detection of visible radiation in nanopatterned MoS2-based photosensors.