Exploiting quantum and phonon interference for molecular thermoelectricity and Seebeck sensing (MoQPI)

在任何电子设备中，电子元件产生的多余热量通常会被浪费掉。热电装置可以通过塞贝克效应将余热转化为电能。通过塞贝克效应从热量中发电是无声的，环保的，并且不需要移动部件。不幸的是，目前的热电材料难以加工，全球供应有限，效率不足以满足当前能源需求的要求。这就是为什么全世界都在竞相开发具有高热电效率的材料。为了实现高性能的热电材料，必须优化电子和声子的输运。由于电子和声子（振动）都表现得像波，它们可以在分子尺度上表现出干涉现象，这可以用来优化它们的传输特性。因此，同时控制电子的室温量子干涉（RTQI）和室温声子干涉（RTPI）有可能支持高效分子热电的新设计策略。这项名为“MoQPI”的提案旨在设计新的高效热电材料，通过在交叉平面（CP）低于10nm的薄膜中利用RTQI和RTPI，将废热转化为电能。交叉平面结构是有利的，因为它们没有平行的热路径通过衬底，可以设计来抑制由声子引起的寄生热导。本奖学金提出的全新CP纳米结构材料将由单分子、自组装单层（sam）分子的平行阵列和夹在金属和/或石墨烯电极之间的范德瓦尔斯（vdW）分子纳米带组成。我将在许多分子体系和vdW分子纳米带中同时开发RTQI和RTPI，以产生新一代高性能热电材料。同时评估分子尺度热电材料中的量子和声子干扰将阐明新一代热电器件的设计策略，从而改变社会对工程和实现高效热电材料的路线的看法。MoQPI还将开发塞贝克效应在鉴别生物传感方面的创新应用。与目前基于电传感的方法相比，使用塞贝克系数进行传感是有利的，因为两种具有相似电导的生物物种可能具有不同的符号或大小的塞贝克系数。此外，生物分子（如DNA核碱基）的电导率非常低，这对于基于电导率的传感来说是个问题，但对于塞贝克传感来说是有利的，因为低电导率通常会导致高塞贝克系数。本提案提出的单分子和分子纳米带塞贝克传感技术将为下一代生物传感技术提供突破性的知识。MoQPI还将探索用于能量收集的混合分子结构。在超薄膜分子层中同时识别RTPI和RTQI增强的能量收集和分子传感是实现在现实世界中具有重要社会和经济影响的新型量子技术的第一步。

In any electrical device, unwanted heat produced by electronic components is usually wasted. A thermoelectric device can convert this waste heat to electricity through Seebeck effect. Generation of electricity from heat via the Seebeck effect is silent, environmentally friendly and requires no moving parts. Unfortunately current thermoelectric materials are difficult to process, have limited global supply and are not sufficiently efficient to meet the requirements of current energy demands. That is why there is a world-wide race to develop materials with a high thermoelectric efficiency. To realise a high-performance thermoelectric material, both electron and phonon transport should be optimised. Since both electrons and phonons (vibrations) behave like waves, they can exhibit interference phenomena at a molecular scale, which could be used to optimise their transport properties. Therefore simultaneous control of room-temperature quantum interference (RTQI) of electrons and room-temperature phonon interference (RTPI) have the potential to underpin new design strategies for efficient molecular thermoelectricity. This proposal, entitled 'MoQPI,' aims to design new highly-efficient thermoelectric materials for converting waste heat into electricity, by exploiting RTQI and RTPI in cross-plane (CP) sub-10nm thin films. Cross-plane structures are advantageous, because they do not suffer parallel heat paths through the substrate and can be engineered to suppress parasitic thermal conductance due to phonons. The radically-new CP nanostructured materials proposed in this Fellowship will be formed from single-molecules, parallel arrays of molecules in self-assembled monolayers (SAMs) and van-der-Waals (vdW) molecular nanoribbons sandwiched between metallic and/or graphene electrodes. I will exploit RTQI and RTPI simultaneously in many molecule systems and vdW molecular nanoribbons to yield a new generation of high-performance thermoelectric materials. Simultaneous assessment of quantum and phonon interference in molecular-scale thermoelectric materials will elucidate design strategies for the development of new generation of thermoelectric devices and consequently will change the community view on routes to engineer and realize highly efficient thermoelectric materials. MoQPI will also develop innovative applications of the Seebeck effect for discriminating biological sensing. Using the Seebeck coefficient for sensing is advantageous compared with current methods based on electrical sensing, because two biological species that might possess similar conductances could have Seebeck coefficients with different signs or magnitudes. Furthermore, the electrical conductances of biomolecules such as DNA nucleobases are extremely low, which is problematic for conductance-based sensing, but advantageous for Seebeck sensing, since low electrical conductances typically lead to high Seebeck coefficients. Seebeck sensing using single molecules and molecular nanoribbons proposed in this proposal will generate ground-breaking knowledge needed for next-generation biosensing. MoQPI will also explore hybrid molecular structures for energy harvesting. The identification of simultaneous RTPI and RTQI enhanced energy harvesting and molecular sensing in ultra-thin-film molecular layers is the first step to realise new types of quantum technologies with important societal and economic impacts in the real world.