Understanding the spin-entangled triplet-pair state in organic semiconductors

了解有机半导体中的自旋纠缠三线对态

• 批准号: 2266426
• 金额: --
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2266426
• 关键词: Understanding; spin; entangled; triplet; pair

In collaboration with theoreticians at the University of Oxford, this project involves studying the fundamental electronic behaviour of excited states in organic semiconductors (specifically 'triplet-pair' states) for applications in photovoltaics, displays and polaritonics. You will study model systems (either thin films, photonic devices or protein-bound semiconductors) using ultrafast spectroscopy at Sheffield's ultrafast laser facility. [[Background]]Singlet fission is a process whereby one photon creates two excited states. This two-for-one mechanism could dramatically increase solar cell efficiency (from 33% to >40%). There has therefore been significant academic and industrial interest in developing new singlet fission sensitizers for photovoltaic or optoelectronic applications recently. Unfortunately, to-date no material has proved ideal. This is in part because of a fundamental lack of understanding of the singlet fission process and what molecular parameters control it. What is known is that singlet fission proceeds through an intermediate excited state, known as (TT): a correlated pair of triplets (spin S=1 excitations). The spins of the individual triplets may remain entangled over microseconds at room temperature, even as the triplets move apart, making it an exciting area of research with possible applications well beyond photovoltaics. [[Project details]]In this project you will study the magnetic-field dependent spectroscopy of organic semiconductors using ultrafast (femtosecond) pulses of light to map the electronic landscape of the singlet fission process in Sheffield's ultrafast laser facility. The emphasis will be on developing an understanding of triplet-pair states (TT): their lifetime and energetics; how long they remain spin-coherent; how far and fast they move. The aim is to understand which molecular and film parameters govern these properties and how they can be optimized for use in a variety of optoelectronic and photonic devices.

该项目与牛津大学的理论家合作，研究有机半导体中激发态（特别是“三重态对”态）的基本电子行为，以应用于光伏、显示器和极化电子。您将在谢菲尔德的超快激光设施中使用超快光谱研究模型系统（薄膜、光子器件或蛋白质结合半导体）。 [[背景]]单态裂变是一个光子产生两个激发态的过程。这种合二为一的机制可以显着提高太阳能电池的效率（从 33% 到 >40%）。因此，最近学术界和工业界对开发用于光伏或光电应用的新型单线态裂变敏化剂产生了浓厚的兴趣。不幸的是，迄今为止还没有任何材料被证明是理想的。部分原因是对单线态裂变过程以及控制它的分子参数缺乏根本性的了解。众所周知，单重态裂变通过中间激发态进行，称为 (TT)：一对相关的三重态（自旋 S=1 个激发）。在室温下，即使三重态分开，单个三重态的自旋也可能在几微秒内保持纠缠，这使其成为一个令人兴奋的研究领域，其可能的应用远远超出了光伏领域。 [[项目详细信息]]在本项目中，您将使用超快（飞秒）光脉冲研究有机半导体的磁场相关光谱，以绘制谢菲尔德超快激光设施中单线态裂变过程的电子图谱。重点是加深对三重态对态（TT）的理解：它们的寿命和能量；它们保持自旋相干的时间有多长；他们移动的距离和速度。目的是了解哪些分子和薄膜参数控制这些特性，以及如何优化它们以用于各种光电和光子器件。