Self-assembled molecular monolayers with ultra-low thermal conductance for energy harvesting (QSAMs)

用于能量收集的具有超低热导的自组装单分子层（QSAM）

• 批准号: EP/P027172/1
• 负责人: Christopher Ford
• 金额: $ 45.95万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FP027172%2F1
• 关键词: Self; assembled; molecular; monolayers; ultra

In single molecules, vibrations due to heat (phonons) and electrons both behave quantum-mechanically like waves and so they can exhibit interference, which can be used to manipulate them. It turns out that constructive or destructive interference of phonons and electrons within individual organic molecules can be engineered precisely by the addition of various atomic groups to the molecule or by carefully selecting the connection of the molecule to external electrodes. Although manipulation of room-temperature quantum interference (RTQI) of electrons in single molecules has been realised recently and is a topic of intense competition between research groups in the UK and abroad, simultaneous control of room-temperature phonon interference (RTPI) has not yet been achieved. This project, called QSAMs, aims to deliver the next breakthrough by designing and realising technologically-relevant materials and devices, which exploit both RTPI and RTQI to yield the next generation of thermoelectric materials.Electricity for information technologies currently results in carbon emissions that are comparable to those of the total global aviation industry. QSAMs aims to address the global challenge of reducing these emissions significantly by inventing new materials that efficiently convert the waste heat produced by data centres (or example) into useful electricity. Our target materials are thin films formed from single layers or a few layers of molecules, sandwiched between flat electrodes. Interference will be used to optimise their ability to convert waste heat into electricity and for on-chip cooling. This will be achieved by modifying the vibrational properties of molecules with a high RTQI-driven Seebeck coefficient, which determines the voltage generated when a temperature difference is applied to the two sides of a molecule or a thin film. Conversely, if a voltage is applied across a molecule, the closely-related Peltier coefficient determines the magnitude of the cooling effect that can be created.A crucial property important for heat recovery (in addition to the electrical conductance and the Seebeck coefficient) is the thermal conductance, which needs to be low. Within a bulk material it is difficult to engineer simultaneously high electrical conductance and low thermal conductance. However, for single molecules or thin molecular films attached to electrodes, the thermal conductance can be engineered by synthesising Christmas-tree-like molecules (connected to the electrodes at top and bottom), in which the trunk of the molecule is connected to branches coming out of the sides, which oscillate in such a way as to cancel out the phonon waves flowing along the trunk. Phonon transport can be further reduced by selecting slippery anchor groups for binding the molecules to the electrodes, in order to scatter phonons at the contacts between the molecules and electrodes. The technical challenges that this proposal addresses are three-fold. The first is to identify theoretically families of molecules that will have the propensity for large RTQI and RTPI effects, and to predict which atomic groups and which anchor groups will optimise their properties. The second is to synthesise these molecules and the third is to measure and optimise their properties in a vast parallel array of molecules, known as a self-assembled monolayer. Understanding the hurdles that need to be overcome to realise simultaneously RTPI and RTQI in such macroscopic ultra-thin-film arrays of molecules will help identify the first steps to a new type of technology that has important societal and economic impacts in the real world and addresses pressing problems of on-chip cooling and energy-efficient heat recovery.

在单个分子中，由于热（声子）而引起的振动和电子都像波浪一样行为量子，因此它们可以表现出干扰，可用于操纵它们。事实证明，可以通过在分子中添加各种原子基团或仔细选择分子与外部电极的连接来精确地设计单个有机分子中的声子和电子的建设性或破坏性干扰。尽管最近已经实现了单分子中电子室温量子干扰（RTQI）的操纵，并且是英国和国外研究组之间激烈竞争的话题，但尚未实现对室温声子干扰（RTPI）的同时控制。该项目称为QSAMS，旨在通过设计和实现与技术相关的材料和设备来实现下一个突破，这些材料和设备都利用了RTPI和RTQI来产生热电学的下一代热电学材料。当前在与全球全球航空公司总体相比的碳发射中，信息技术的电动性。 QSAMS旨在通过发明有效将数据中心（或示例）产生的废热转换为有用的电力来大大减少这些排放的全球挑战。我们的目标材料是由单层或几层分子形成的薄膜，这些分子夹在平坦的电极之间。干扰将用于优化其将废热转化为电和芯片冷却的能力。这将通过用高RTQI驱动的Seebeck系数修改分子的振动特性来实现这一目标，该系数确定当将温度差施加到分子或薄膜的两侧时产生的电压。相反，如果在分子上施加电压，与密切相关的毛发系数确定了可以产生的冷却效应的大小。对热恢复的重要特性（除了电导和Seebeck系数外，重要的是导热率），需要较低。在散装材料中，很难同时设计高电导率和低导电电导率。但是，对于连接到电极的单分子或薄分子膜，可以通过合成圣诞节树状分子（连接到顶部和底部的电极）来设计热电导，该分子的躯干与侧面的分支相连，以取消单音旋转的方式，以取消流动量流动。可以通过选择湿滑的锚固组将分子与电极结合，以进一步降低声子传输，以便在分子和电极之间的触点处散射声子。该提案解决的技术挑战是三个方面。首先是识别理论上的分子家族，这些家族将对大型RTQI和RTPI效应具有倾向，并预测哪些原子基团以及哪些锚固组将优化其性质。第二个是合成这些分子，第三个是在广泛的平行分子阵列中测量和优化其性能，称为自组装单层。了解需要克服的障碍以同时实现这种宏观超薄膜分子阵列中的RTPI和RTQI，这将有助于确定具有重要的社会和经济影响的新型技术的第一步，并解决了现实世界中具有重要的社会和经济影响，并解决了对智障冷却和能量效果的紧迫问题。

项目成果

Nanoscale Thermal Transport in 2D Nanostructures from Cryogenic to Room Temperature

• DOI: 10.1002/aelm.201900331
• 发表时间: 2019-08
• 期刊: Advanced Electronic Materials
• 影响因子: 6.2
• 作者: C. Evangeli;J. Spièce;S. Sangtarash;A. Molina‐Mendoza;M. Mucientes;T. Mueller;C. Lambert;H. Sadeghi;O. Kolosov

Tuning the thermoelectrical properties of anthracene-based self-assembled monolayers.

• DOI: 10.1039/d0sc02193h
• 发表时间: 2020-07-14
• 期刊: Chemical science
• 影响因子: 8.4
• 作者: Ismael A;Wang X;Bennett TLR;Wilkinson LA;Robinson BJ;Long NJ;Cohen LF;Lambert CJ
• 通讯作者: Lambert CJ

Electrostatic Fermi level tuning in large-scale self-assembled monolayers of oligo(phenylene-ethynylene) derivatives.

低聚（亚苯基-乙炔基）衍生物大规模自组装单层的静电费米能级调谐。

• DOI: 10.1039/d2nh00241h
• 发表时间: 2022
• 期刊: Nanoscale horizons
• 影响因子: 9.7
• 作者: Wang X

Optimised power harvesting by controlling the pressure applied to molecular junctions.

• DOI: 10.1039/d1sc00672j
• 发表时间: 2021-03-04
• 期刊: Chemical science
• 影响因子: 8.4
• 作者: Wang X;Ismael A;Almutlg A;Alshammari M;Al-Jobory A;Alshehab A;Bennett TLR;Wilkinson LA;Cohen LF;Long NJ;Robinson BJ;Lambert C
• 通讯作者: Lambert C

High-yield parallel fabrication of quantum-dot monolayer single-electron devices displaying Coulomb staircase, contacted by graphene.

• DOI: 10.1038/s41467-021-24233-2
• 发表时间: 2021-07-14
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Fruhman JM;Astier HPAG;Ehrler B;Böhm ML;Eyre LFL;Kidambi PR;Sassi U;De Fazio D;Griffiths JP;Robson AJ;Robinson BJ;Hofmann S;Ferrari AC;Ford CJB
• 通讯作者: Ford CJB