Collaborative Research: A Roadmap Toward Terahertz Optoelectronics Using Active Control of Charge Density Waves at Degenerate Semiconductor Interfaces

合作研究：利用简并半导体界面电荷密度波的主动控制实现太赫兹光电子学的路线图

• 批准号: 1611231
• 负责人: Daniel Wasserman
• 金额: $ 25.5万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1611231&HistoricalAwards=false
• 关键词: Collaborative; Research; Roadmap; Toward; Terahertz

The information revolution of the past decades has been driven by unprecedented advances in microprocessor technology and a continuous progression towards smaller, faster and more efficient electronic devices. As a result, remarkable new capabilities have been enabled across vastly different areas of human activity such as telecommunication, computation, finances, national security and space exploration. Despite this progress, the past few years has seen scaling issues associated with electronic interconnect delay times and heat dissipation result in the saturation of microprocessor clock speeds at about 3GHz. Photonic integrated circuits, being the analogue of electronic circuits but with photons substituting for electrons as the information carrier, possess an exceedingly high data-carrying capacity and have the potential to address some of the present bottlenecks in microprocessor technology. However, the dielectric waveguides and interconnects currently used in photonic circuits are limited in size by the fundamental law of diffraction, leading to dimensional mismatch between electronic and photonic components. As a result, their practical implementation in real-world devices, apart from telecommunications, has been substantially hindered. Here we propose a new data processing element, an optoelectronic switch, which assimilates the best characteristics of photonics and electronics. It has the potential to address the current information bandwidth limitations of electronic devices, while simultaneously enabling device sizes that are substantially smaller than traditional photonic elements. A significant impact of this work will be the fostering of cutting-edge research opportunities for graduate and undergraduate students, including from underrepresented groups, implementing a new teaching methodology and pursuing a broader outreach by engaging high school children with fascinating topics in math and sciences. This proposal seeks to develop a new optoelectronic device, referred to as Surface Plasmon Diode, with operation based on active control of charge-density waves propagating at heavily doped (degenerate) semiconductor interfaces. A synergy between theory and experiment will be pursued to gain insight into the complex multi-physics phenomena behind the device operation, including charge transport and recombination at high-gradient, heavily doped pn+- junctions, spatially and time dependent local permittivity variations at the semiconductor interfaces, and thermal effects due to Ohmic heating and electromagnetic energy dissipation. The experimental efforts will lead to Proof of Concept devices based on Silicon-on-Insulator and epitaxially-grown III-V semiconductor materials and compounds. Bulk material growth/fabrication and characterization will inform the theoretical modeling, which in turn will guide the fabrication and experimental characterization of the prototype. The transient response of the devices will be tested using a direct detection method (IR-detector) for modulation rates ranging from low (kHz) to moderate and high frequencies (few MHz up to 3GHz). For data rates higher than 3GHz a new on-chip electro-optical detection will be implemented. These experimental measurements, in conjunction with the theory, will establish the physical limitations and scaling laws governing the device 3dB bandwidth, and establish a clear roadmap toward direct, electro-optical signal modulation at rates down to the picosecond time scale for signal modulation surpassing -10dB and mode sizes that are substantially smaller compared to present-day optoelectronics elements. The proposed research presents a new approach toward fast optical interconnects, circuitry and logic elements and may lead to breakthrough technologies related to integrated optics and electronics, a multibillion dollar industry.

过去几十年的信息革命是由微处理器技术的空前进步和向更小、更快、更高效的电子设备的不断发展推动的。其结果是，在电信、计算、金融、国家安全和太空探索等人类活动的不同领域，都实现了非凡的新能力。尽管取得了这些进展，但在过去的几年里，与电子互连延迟时间和散热相关的缩放问题导致微处理器时钟速度在3GHz左右饱和。光子集成电路是电子电路的模拟，但以光子代替电子作为信息载体，具有极高的数据承载能力，有潜力解决目前微处理器技术的一些瓶颈。然而，目前用于光子电路的介质波导和互连受到衍射基本定律的限制，导致电子和光子元件之间的尺寸不匹配。因此，它们在现实世界设备中的实际实施，除了电信，已经大大阻碍了。本文提出了一种新的数据处理元件——光电开关，它融合了光子学和电子学的最佳特性。它有潜力解决当前电子设备的信息带宽限制，同时使设备尺寸比传统光子元件小得多。这项工作的一个重要影响将是为研究生和本科生（包括来自代表性不足的群体）提供前沿研究机会，实施一种新的教学方法，并通过让高中生参与有趣的数学和科学主题来追求更广泛的推广。本提案旨在开发一种新的光电器件，称为表面等离子体二极管，其操作基于主动控制在重掺杂（简并）半导体界面传播的电荷密度波。理论和实验之间的协同作用将被追求，以深入了解器件运行背后复杂的多物理现象，包括高梯度下的电荷输运和复合，高掺杂pn+结，半导体界面的空间和时间相关的局部介电常数变化，以及由于欧姆加热和电磁能量耗散引起的热效应。实验工作将导致基于绝缘体上硅和外延生长III-V半导体材料和化合物的概念验证设备。大块材料的生长/制造和表征将为理论建模提供信息，理论建模反过来将指导原型的制造和实验表征。器件的瞬态响应将使用直接检测方法（红外探测器）对从低（kHz）到中高频（几MHz到3GHz）的调制速率进行测试。对于高于3GHz的数据速率，将实施一种新的片上光电检测。这些实验测量，结合理论，将建立控制设备3dB带宽的物理限制和缩放规律，并建立一个明确的路线图，直接的电光信号调制速率降至皮秒时间尺度，信号调制超过-10dB，与目前的光电元件相比，模式尺寸要小得多。这项研究提出了一种快速光学互连、电路和逻辑元件的新方法，并可能导致与集成光学和电子相关的突破性技术，这是一个价值数十亿美元的产业。