Collaborative Research: Tellurene mid-infrared integrated photonics

缺乏与普通半导体衬底兼容的光学材料是中红外领域集成光子器件开发的一个障碍。该奖项支持一个合作团队进行基础研究，以推进新兴光学纳米材料与中红外光子学平台的整合。该研究旨在实现基于新型光学纳米材料（即二维（2-D）碲烯）的中红外光子元件和电路的设计，制造和集成。碲烯是元素碲的原子薄晶体，是一种新兴的2-D材料，适合于可规模化合成，并且独特地结合了小且可调的带隙能量、高载流子迁移率、异常大的电光活性和上级化学稳定性，这使其成为中红外光子学的有前途的和通用的材料平台。中红外光谱带（2-20微米）对于热成像、光谱传感、红外对抗和自由空间通信具有重要的技术意义。所提出的基于碲的器件平台一旦得到证实，将对中红外集成光子学产生变革性影响。所设想的探测器和调制器设备都被预测具有远远超过最先进的性能。这项研究涉及多个学科，包括材料科学，电气工程，光子学，器件物理，制造和化学。多学科研究与拟议的外联活动相结合，将为学生提供接触尖端纳米技术和光学科学的宝贵机会，激发他们对STEM职业道路的兴趣。2-D材料已成为光子集成的一个有前途的材料组，因为它们具有传统块状和薄膜材料所没有的独特光学特性。然而，一些科学和技术障碍尚未被克服，以实现中红外集成光子学的2-D材料的全部应用潜力。本研究填补了溶液合成碲与中红外光子学平台集成的知识空白。目的是（1）展示基于碲烯的高性能波导集成室温中红外光电探测器和超快电光调制器，以及（2）探索溶液合成碲烯作为集成中红外光子器件的新型光学材料的独特优势和能力。该研究小组将创新一种加工方案，使用合成工程硫属化物玻璃作为光导介质和红外透明栅极电介质，直接在碲上制造波导结构。这种单片方法利用了宽带中红外透明性和硫族化物玻璃的近室温处理，不仅简化了集成过程，而且还允许光子电路进行专门优化，并以光刻精度精确对准碲晶体。该团队还将开发一个基于物理的框架，以设计和指导材料合成，设备制造和系统集成。该奖项反映了NSF的法定使命，并已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进行评估的支持。

Lack of optical materials compatible with common semiconductor substrates presents a standing hurdle for integrated photonic device development in the mid-IR domain. This award supports a collaborative team to conduct fundamental research to advance knowledge for the integration of emerging optical nanomaterials with the mid-IR photonics platform. The research aims to enable the design, fabrication, and integration of mid-IR photonic components and circuits based on a new optical nanomaterial, namely two-dimensional (2-D) tellurene. Tellurene, atomically thin crystals of elemental tellurium, is an emerging 2-D material amenable to scalable synthesis and uniquely combines small and tunable bandgap energies, high carrier mobility, exceptionally large electro-optic activity, and superior chemical stability, which makes it a promising and versatile material platform for mid-IR photonics. The mid-IR spectral band (2-20 micro-meter) is of significant technological importance for thermal imaging, spectroscopic sensing, infrared countermeasures, and free-space communications. The proposed tellurene-based device platform, once demonstrated, will have a transformative impact on mid-IR integrated photonics. The envisioned detector and modulator devices both are predicted to have performances far exceeding the state-of-the-art. This research involves several disciplines, including materials science, electrical engineering, photonics, device physics, manufacturing, and chemistry. The multi-disciplinary research combined with the proposed outreach activities will provide valuable opportunities for exposing the students to cutting-edge nanotechnology and optical sciences to inspire their interest in STEM career paths.2-D materials have emerged as a promising material group for photonic integration, given their singular optical properties not found in conventional bulk and thin-film materials. However, some scientific and technical barriers are yet to be overcome to realize the full application potential of 2-D materials for mid-IR integrated photonics. This research is to fill the knowledge gap on the integration of solution-synthesized tellurene with the mid-IR photonics platform. The objectives are (1) to demonstrate high-performance waveguide integrated room-temperature mid-IR photodetectors and ultrafast electro-optic modulators based on tellurene, and (2) to explore the unique advantage and capability of solution-synthesized tellurene as a novel optical material for integrated mid-IR photonic devices. The research team will innovate a processing scheme that directly fabricates waveguide structures on tellurene using compositionally-engineered chalcogenide glass as both the light guiding medium and an infrared-transparent gate dielectric. This monolithic approach capitalizes on the broadband mid-IR transparency and near-room-temperature processing of chalcogenide glass to not only simplify the integration process but also allow the photonic circuit to be specifically optimized and precisely aligned to tellurene crystals with lithographic accuracy. The team will also develop a physics-based framework to design and guide the material synthesis, device fabrication, and system integration.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.