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都会被浪费掉。热电装置可以通过塞贝克效应将这些余热转化为电能。通过塞贝克效应利用热量发电是一种安静、环保的方式，而且不需要移动部件。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的能源需求。这就是为什么世界各地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，电子和声子的输运都应该得到优化。由于电子和声子(振动)的行为都像波，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)具有支持高效分子热电的新设计策略的潜力。这项名为“MoQPI”的提议旨在通过在跨平面(CP)亚10 nm薄膜中利用RTQI和RTPI来设计用于将废热转化为电能的新型高效热电材料。跨平面结构是有利的，因为它们不会受到通过衬底的平行热路径的影响，并且可以被设计成抑制由于声子引起的寄生热导。本研究中提出的全新的CP纳米结构材料将由夹在金属和/或石墨烯电极之间的单分子、平行分子阵列的自组装单分子层(SAM)和范德华(VDW)分子纳米带组成。我将在许多分子系统和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开发新一代热电器件的设计策略，从而改变人们对设计和实现高效热电材料的途径的看法。MoQPI还将开发Seebeck效应的创新应用，以区分生物传感。与目前基于电学传感的方法相比，使用塞贝克系数进行传感是有利的，因为可能具有相似电导的两个生物物种可能具有不同符号或大小的塞贝克系数。此外，生物分子如DNA碱基的电导极低，这对于基于电导的传感是有问题的，但对于Seebeck传感是有利的，因为低电导通常会导致高的Seebeck系数。这项提议中提出的使用单分子和分子纳米带的Seebeck传感将产生下一代生物传感所需的开创性知识。MoQPI还将探索用于能源收集的杂化分子结构。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在现实世界中实现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.