Long range charge transport in Molecular Electronic devices

分子电子器件中的长程电荷传输

• 批准号: RGPIN-2015-05991
• 负责人: Mccreery, Richard
• 金额: $ 4.3万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=690867
• 关键词: Long; range; charge; transport; Molecular

The field of molecular electronics (ME) seeks to enhance electronic functions of conventional microelectronic devices by incorporating molecules into electronic circuits to improve performance, lower costs, reduce power demands and provide novel electronic functions. Our group was the first to develop a reliable, reproducible molecular junction with sufficient lifetime (~ years) and temperature tolerance (-260 to +300 °C) for practical applications. This junction enabled an audio processing function not possible with silicon, and a prototype developed in 2014 is currently being evaluated for commercialization in an audio accessory market exceeding $2B/year worldwide. Of particular importance in such devices are the electron transport mechanisms over distances in the 1-25 nm range, which differ fundamentally from the transport in either conventional semiconductors or in the thicker films (>50 nm) in widely studied "organic" electronics. We plan to explore novel transport mechanisms that exploit molecular orbitals for charge transport, with the ultimate objective of rationally designing novel electronic behaviours using variations in molecular structure. We have reported initial results on an ionization mechanism strongly dependent on molecular structure and operative over 5-20 nm, distances too great for quantum mechanical tunneling. A transport distance range of 1-25 nm not only avoids the pitfalls of "organic electronics" but also enables "ballistic" transport, which can enable very high frequency operation (>1000 GHz). We will use the robust molecular junction structure developed over the past decade to pursue three related fundamental subprojects on how molecular structure affects electronic behaviour:***Project 1: Structural Control of Transport. Thiophene derivatives with similar structures but varying energy levels will be investigated in the distance range beyond tunneling (i.e., 5-20 nm), where we have observed strong effects of orbital energies. We will investigate the effects of variations in orbital energies to resonant transport, field ionization, and ballistic transport mechanisms.***Project 2: Bi-layer and Tri-layer Junctions. Differences in orbital energies of adjacent molecular layers are expected to cause rectification and possibly resonance between the contacts and molecular orbitals. We will study the effects of orbital energies on transport to help formulate the "design rules" of molecular electronic behaviour.***Project 3: Optical Monitoring of Working Molecular Devices. In addition to verifying device structures via spectroscopy, we will investigate device photocurrents and light emission as probes of internal energy levels and ballistic transport.***These projects have the potential to lead to an entire new class of microelectronics based on molecular junctions with valuable functions and behaviours distinct from those of silicon.**

分子电子学领域致力于通过在电子电路中加入分子来增强传统微电子器件的电子功能，以提高性能、降低成本、减少功率需求并提供新的电子功能。我们团队率先开发出可靠、可重复使用的分子结，具有足够的寿命(~年)和耐温(-260至+300°C)，可用于实际应用。这种连接实现了硅无法实现的音频处理功能，2014年开发的一款原型目前正在全球音频配件市场进行商业化评估，市场规模超过每年20亿美元。在这类器件中，特别重要的是在1-25 nm范围内的电子传输机制，这从根本上不同于传统半导体或被广泛研究的“有机”电子器件中较厚的薄膜(&gt；50 nm)中的传输。我们计划探索利用分子轨道进行电荷传输的新的传输机制，最终目标是利用分子结构的变化合理地设计新的电子行为。我们已经报道了电离机制的初步结果，这种电离机制强烈依赖于分子结构，工作范围为5-20 nm，距离太大，无法进行量子力学隧穿。1-25 nm的传输距离范围不仅避免了“有机电子学”的陷阱，而且还实现了“弹道”传输，从而实现了非常高的频率操作(&gt；1000 GHz)。我们将利用过去十年发展出的强大的分子结结构，就分子结构如何影响电子行为进行三个相关的基础子项目：*项目1：运输的结构控制。结构相似但能级不同的噻吩衍生物将在隧穿以外的距离范围内(即5-20 nm)进行研究，在那里我们观察到了强烈的轨道能量效应。我们将研究轨道能量的变化对共振传输、场电离和弹道传输机制的影响。*项目2：双层和三层结。相邻分子层的轨道能量的差异有望引起接触和分子轨道之间的整流和可能的共振。我们将研究轨道能量对输运的影响，以帮助制定分子电子行为的“设计规则”。*项目3：工作分子器件的光学监测。除了通过光谱学验证器件结构外，我们还将研究器件光电流和光发射作为内部能级和弹道传输的探测器。*这些项目有可能导致基于分子结的全新微电子类别，具有与硅不同的有价值的功能和行为。**