Collaborative Research: Chemisorption-Induced Ultraviolet Quantum Well Optoelectronic Materials

合作研究：化学吸附诱导的紫外量子阱光电材料

• 批准号: 1608887
• 负责人: Jonathan Spanier
• 金额: $ 30万
• 依托单位: Drexel University
• 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: 2016-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1608887&HistoricalAwards=false
• 关键词: Collaborative; Research; Chemisorption; Induced; Ultraviolet

Nontechnical Description: Next-generation devices require new classes of materials capable of advanced (multi-) functional response. In this regard, complex-oxide materials and interfaces have the potential for far-reaching impact. Of particular interest are opportunities to harness novel light-matter interactions to enable a range of applications. Controlling such interactions requires exacting production of materials and in-depth understanding of the mechanism(s) underlying the phenomena. For example, semiconductor heterostructures drive optoelectronics for solid-state lighting, communications, computing, and sensing and the subsequent introduction of nitride- and simple oxide-based materials has helped pushed such technologies into the ultraviolet emission range. New functionalities involving ultraviolet-emitting devices may enable faster encoding and manipulation of information, new modes of chemical detection and sensing, and more efficient solid-state lighting. This project explores opportunities for on-demand complex oxide-electronics through local material reconfiguration. It builds upon discoveries of conductivity at the interface of two insulators, and demonstration of reversible, local manipulation of conductance to produce tunable ultraviolet-light emission from such materials. The project actively promotes the training of next-generation scientists and engineers in technologically important and relevant fields critical for the sustained economic vitality of the United States, focuses efforts on the mentoring and training of students from historically underrepresented groups, and provides research co-op and international research experiences for student trainees.Technical Description: In this project, a new optoelectronic materials paradigm is defined by the coupling of spatially- and chemically-selective chemisorption with sub-surface quantum well(s) formed at the interface(s) of two band insulators. Symmetry-breaking and electrostatic potential mismatch between constituent semiconductors at an interface results in novel phenomena inaccessible in the bulk. This emergent phenomena can, in some systems, be tuned extensively since a surface, and to some extent, an interface, is free to reconstruct structurally and electronically. Bringing a surface or sub-surface into equilibrium with a controlled environment enables local, reversible control of the electronic phase or functional state. The effects of adsorbate type and locality, of a symmetry-lowering field on the strength, energy, and spatial response of ultraviolet luminescence from one or more distinct sub-surface, two-dimensional electron liquid(s) exhibiting electron correlations are studied. In particular, the activities focus on understanding and ultimately controlling several distinguishing features: 1) how the steady-state ultraviolet light emission intensity changes in response to different adsorbates; 2) how the physical properties of the model system, as probed by changes in spectral emission, respond to externally applied fields; 3) how the ultraviolet luminescence, including locality and stability, can be controlled with external stimuli; and 4) what the introduction of multiple, closely-spaced quantum wells and/or other oxide heterojunction materials does to the response. These investigations advance understanding of radiative recombination in new model optoelectronic ultraviolet light-emitting systems defined not by bulk, interfacial or surface properties alone, but by coupling of sub-surface interfacial quantum well electronic structure to surface chemisorption.

非技术描述：下一代设备需要能够进行高级（多功能）功能响应的新型材料。在这方面，复合氧化物材料和界面具有产生深远影响的潜力。特别令人感兴趣的是利用新颖的光与物质相互作用来实现一系列应用的机会。控制这种相互作用需要精确地生产材料并深入了解这些现象背后的机制。例如，半导体异质结构推动了用于固态照明、通信、计算和传感的光电子学，随后氮化物和简单氧化物基材料的引入帮助将此类技术推向了紫外线发射范围。涉及紫外线发射设备的新功能可以实现更快的信息编码和操作、化学检测和传感的新模式以及更高效的固态照明。该项目通过局部材料重新配置探索按需复杂氧化物电子器件的机会。它建立在两个绝缘体界面电导率的发现之上，并演示了电导率的可逆、局部操纵以从此类材料产生可调谐的紫外光发射。该项目积极促进对美国持续经济活力至关重要的重要技术和相关领域的下一代科学家和工程师的培训，重点关注对来自历史上代表性不足群体的学生的指导和培训，并为学生学员提供研究合作和国际研究经验。 技术描述：在该项目中，通过空间和空间耦合定义了一种新的光电材料范式。 化学选择性化学吸附，在两个能带绝缘体的界面处形成亚表面量子阱。界面处的组成半导体之间的对称性破缺和静电势不匹配导致了在整体中无法实现的新现象。在某些系统中，这种新出现的现象可以进行广泛的调整，因为表面（在某种程度上，界面）可以自由地进行结构和电子重建。使表面或次表面与受控环境达到平衡，可以实现对电子相或功能状态的局部、可逆控制。研究了吸附物类型和局部性、对称性降低场对来自一个或多个不同次表面、表现出电子相关性的二维电子液体的紫外发光的强度、能量和空间响应的影响。特别是，这些活动侧重于理解并最终控制几个显着特征：1）稳态紫外光发射强度如何响应不同的吸附物而变化； 2）通过光谱发射的变化探测模型系统的物理特性如何响应外部施加的场； 3）如何通过外部刺激来控制紫外发光，包括局部性和稳定性； 4) 引入多个紧密间隔的量子阱和/或其他氧化物异质结材料对响应有何影响。这些研究促进了对新模型光电紫外发光系统中辐射复合的理解，该系统不是仅由体、界面或表面特性定义，而是通过亚表面界面量子阱电子结构与表面化学吸附的耦合来定义。