CAREER: Graphene-hexagonal Boron Nitride (hBN) Heterostructure Infrared Polaritonic Devices

摘要标题：采用石墨烯-六方氮化硼层状异质结构的红外器件非技术描述：覆盖6到15微米波长的红外器件在许多光学技术中发挥着关键作用，如热成像、夜视和自由空间光通信。进入这个红外窗口最常用的材料是碲化镉汞。然而，碲化镉汞的生长涉及有毒元素，因此具有很高的挑战性。此外，它又软又脆，给器件制造和系统集成带来了困难。在这个项目中，首席研究员和他的团队将探索一种基于层状石墨烯-六方氮化硼异质结构的替代材料体系，用于红外设备应用。他们将重点研究红外光与异质结构的相互作用，并优化其红外性能。此外，该团队将建造能够在6至15微米的波长范围内执行红外光探测功能的红外设备。该计划还将培养学生和博士后，从而为国家在光学和半导体行业的劳动力需求做出贡献。该项目将在一个迅速崛起的领域为学生提供独特的动手研究培训，同时让他们接触到多学科的研究方法。与耶鲁大学科学之路合作，该项目还将教育纽黑文地区来自不同背景和种族的预科学生，特别是代表不足的群体，灌输他们对科学和工程的兴趣。技术描述：极化子是由光子与携带电偶极的基本激发(如等离子激子、声子或激子)耦合而产生的准粒子。在这里，首席研究员和他的团队将探索覆盖从6到15微米的重要中红外波长范围的基于石墨烯的红外极化子器件。他们将研究由石墨烯和六方氮化物(HBN)组成的大面积混合结构中的等离子体激元、声子和等离子体声子-声子极化子。总体目标是实现前所未有的光-物质相互作用，并实现高性能的红外极化成像元件。这一提议的关键要素是利用极化共振增强光-石墨烯相互作用。这位原理研究者提出了两个互补的推动：(1)了解石墨烯-hBN异质结中的等离子体、声子和等离子体-声子极化子及其衰减过程，并基于横向纳米带结构建中红外(6-15微米)的极化子光电探测器；(2)了解垂直异质结中以热载流子为主的热电子发射效应，并利用热载流子热电子发射构建极化子增强光电探测器。这项拟议的研究将导致基于替代材料系统的新光学器件。对等离子体、声子和等离子体声子-声子极化子及其衰减途径的系统研究将在二维层状材料中带来新的光学物理发现。

Abstract Title: Infrared Devices using Graphene-hexagonal Boron Nitride Layered HeterostructuresNontechnical description:Infrared devices covering a wavelength range from 6 to 15 microns can play a critical role in many optical technologies such as thermal imaging, night vision and free-space optical communications. The most commonly used material for the access to this infrared window is mercury cadmium telluride. However, the growth of mercury cadmium telluride involves toxic elements and hence is highly challenging. Moreover, it is soft and brittle, leading to difficulties in device fabrication and system integration. In this program, the principle investigator and his team will explore an alternative material system based on layered graphene-hexagonal boron nitride heterostructures for the infrared device applications. They will focus on the interaction of infrared light and the heterostructures and optimize their infrared properties. Furthermore, the team will built infrared devices which can perform infrared light detection functions in the wavelength range from 6 to 15 microns. This program will also train students and postdocs and hence contribute to the nation's workforce needs in optics and semiconductor industries. The program will provide students with unique hands-on research training in a rapidly emerging field, while exposing them to multidisciplinary research approaches. In collaboration with Yale Pathways to Science, this program will also educate pre-college students in New Haven area from diverse backgrounds and ethnicities especially under-represented groups, instilling their interests in science and engineering.Technical description: Polaritons are quasiparticles resulting from the coupling of photons with electric dipole-carrying elementary excitations such as plasmons, phonons, or excitons. Here the principle investigator and his team will explore graphene based infrared polaritonic devices covering an important mid-infrared wavelength range from 6 to 15 µm. They will investigate plasmon, phonon, and plasmon-phonon polaritons in large area hybrid structures consisting of graphene and hexagonal born nitride (hBN). The overall goals are to achieve unprecedented light-matter interaction and to realize high performance polaritonic imaging elements in the infrared. The key element of this proposal is the enhanced light-graphene interaction using polaritonic resonances. The principle investigator proposes two complementary thrusts: (1) Understand the plasmon, phonon, and plasmon-phonon polaritons and their damping processes in graphene-hBN heterostructures and build polaritonic photodetectors in mid-infrared (6 to 15 µm) based on lateral nanoribbon junctions; and (2) Understand the hot-carrier dominated thermionic emission effect in vertical heterostructures and build polariton enhanced photodetectors utilizing hot-carrier thermionic emission. The proposed research will lead to new optical devices based on an alternative material system. Systematic study on plasmon, phonon, and plasmon-phonon polaritons including their damping pathways will lead to discoveries of new optical physics in two-dimensional layered materials.