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发展的一个长期障碍。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集成。该研究旨在实现基于一种新型光学纳米材料，即二维碲的中红外光子元件和电路的设计、制造和集成。碲是元素碲的原子薄晶体，是一种新兴的二维材料，可扩展合成，独特地结合了小而可调的带隙能量，高载流子迁移率，特别大的电光活性和优越的化学稳定性，这使其成为中红外光子学的一个有前途的多功能材料平台。中红外波段（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。提出的基于碲的器件平台，一旦被证明，将对中红外集成光子学产生变革性的影响。设想的探测器和调制器装置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、电子工程、光子学、器件物理、制造和化学。多学科研究结合拟议的外展活动将为学生提供接触尖端纳米技术和光学科学的宝贵机会，以激发他们对STEM职业道路的兴趣。由于二维材料具有传统块状和薄膜材料所不具有的独特光学特性，它已成为光子集成的一种有前途的材料群。然而，要充分发挥二维材料在中红外集成光子学中的应用潜力，还需要克服一些科学和技术障碍。本研究旨在填补溶液合成碲与中红外光子平台集成的知识空白。目的是(1)展示基于碲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；(2)探索溶液合成碲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。研究小组将创新一种加工方案，直接在碲上制造波导结构，使用合成工程硫系玻璃作为光引导介质和红外透明栅极介质。这种单片方法利用了硫系玻璃的宽带中红外透明度和近室温处理，不仅简化了集成过程，而且还允许光子电路被专门优化并精确地对准碲酸盐晶体，具有光刻精度。该团队还将开发一个基于物理的框架来设计和指导材料合成、设备制造和系统集成。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。

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.