Photo-induced charge and energy transport: from single molecules to disordered materials

光诱导电荷和能量传输：从单分子到无序材料

• 批准号: RGPIN-2017-05119
• 负责人: Kelly, Aaron
• 金额: $ 1.53万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=747939
• 关键词: Photo; induced; charge; energy; transport

My research interests center on the flow of energy and electric charge in, and between, molecules. Chemical energy and electric charge flow during fundamental chemical reaction events, such as when a molecule changes shape, or transfers an electron to one of its neighbors. These processes are especially important when a molecular system interacts with light; after the light energy is absorbed the system must then find some way to “relax”. Describing these sorts of processes from a theoretical perspective requires the development and application of simulation methods that lie at the interface of statistical mechanics and quantum dynamics. Combining these areas is essential to accurately capture these fundamental chemical steps in many forefront problems ranging from solar energy conversion and chemical catalysis to biological sensing and signaling. Molecular simulations of this type can help uncover the underlying mechanisms that lie at the heart of many energy conversion problems, and the ultimate goal of my research program is to extend and apply these approaches to study light-initiated charge and energy transport. In general, studying charge and energy transfer problems in molecular systems is an essential step to engineering new systems that can be manipulated in order to achieve desired outcomes. For example, our current understanding of how naturally occurring systems, such as plants and bacteria, harvest and harness energy from the sun lacks the detail necessary to provide a sufficient set of “design principles” for the development of improved synthetic light-harvesting systems that can perform similar functions. The challenge inherent in these problems is that the behavior of the quantum system is determined by interactions with its environment. These interactions can span many natural time and length scales, and the environment can be disordered. Bridging length and time-scales in molecular simulation is a long-standing holy grail' problem in the research community. Indeed, emerging computational infrastructures continue to push the boundaries in terms of the systems and processes that can be treated. However, these computational speed-ups are far out-paced by the inherent exponential scaling of the equations of quantum mechanics. For this reason, new dynamics algorithms are currently needed in order to access the relevant length and time-scales in, for example, the fundamental processes at play in a solar cell or a light-harvesting bacterium. These insights into how molecular systems and their environments can be tuned to alter their functionality will lead to a deeper understanding of how to leverage molecular-level design principles to aid in the development of improved solar energy conversion materials, molecular electronics, and catalytic systems. Hence, the impact of this work will have importance in many other areas of chemistry, in physics, and in materials science.

我的研究兴趣集中在分子中以及分子之间的能量和电荷流。基本化学反应事件期间的化学能和电荷流，例如分子改变形状或将电子转移到其邻居之一时。当分子系统与光相互作用时，这些过程尤其重要。吸收光能后，必须找到一些“放松”的方法。从理论角度描述这些过程，需要开发和应用模拟方法，这些方法位于统计机制和量子动力学的界面上。结合这些区域对于精确捕获这些基本化学步骤在许多最前沿问题中至关重要，从太阳能转化和化学催化到生物敏感性和信号传导不等。这种类型的分子模拟可以帮助发现许多能量转换问题核心的潜在机制，而我的研究计划的最终目标是扩展和应用这些方法来研究光发射的电荷和能量运输。通常，研究分子系统中的电荷和能量转移问题是工程新系统的重要步骤，以实现预期的结果。例如，我们目前对天然发生的系统（例如植物和细菌，收获和利用太阳的能量）的理解缺乏提供一组足够的“设计原理”所需的细节，以开发改进的合成光收获系统，从而可以执行类似的功能。这些问题固有的挑战在于，量子系统的行为取决于与环境的相互作用。这些相互作用可以跨越许多自然的时间和长度尺度，并且环境可能是无序的。分子模拟中的桥接长度和时间尺度是研究界的长期圣杯。确实，新兴的计算基础架构继续在可以处理的系统和过程方面推动边界。但是，这些计算加速器的量子量表的量子缩放量远远超出了量子力学方程。因此，目前需要新的动力学算法来访问相关的长度和时间尺度，例如，在太阳能电池或轻度收获的细菌中发挥作用的基本过程。这些关于如何调整分子系统及其环境以改变其功能的洞察力将使人们对如何利用分子级设计原理有更深入的了解，以帮助开发改进的太阳能转化材料，分子电子和催化系统。因此，这项工作的影响将在化学，物理学和材料科学领域的许多其他领域都具有重要意义。