Development and application of relativistic propagator methods for accurate theoretical descriptions of organic triplet emitters

相对论传播器方法的开发和应用，用于有机三线态发射体的精确理论描述

• 批准号: 282000297
• 负责人: Professor Dr. Andreas Dreuw, since 5/2018
• 金额: --
• 依托单位: Chair of Theoretical and Computational Chemistry
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/282000297?language=en
• 关键词: Development; application; relativistic; propagator; methods

Organic electronics is one of the future key technologies due to its broad applicability and low energy consumption. In contrast to semiconductor devices, that are to be described by methods of solid state physics, organic electronics is based on molecular structures necessitating different quantum chemical approaches. In both cases numerical requirements are very high asking for the development of efficient theoretical methods in order to gain deep insight and to keep up with technological progress. In this project we focus on organic triplet emitters containing heavy transition metals that are exhibiting very high quantum yields. This high efficiency can be achieved by providing mechanisms that lead to a nearly complete recombination of each injected electron/hole pair into the material. This exciton is localized at the emitting center and shows a statistical mixture of 25% singlet and 75% triplet character. The triplet excitons are not directly amenable to recombination which changes drastically if heavy transition metals are introduced to the complex. Hereby also the triplet states recombine very efficiently by presence of strong spin-orbit coupling (SOC). Therefore, an accurate description of all effects caused by the introduction of heavy atoms, the inclusion of electron correlation and of the environment is therefore mandatory for the design of new efficient triplet emitters. An ideally suited method to achieve this was developed in our group and is based on the fully relativistic polarization propagator. Methods applied so far often introduce approximative treatments of SOC or are quite complex in their handling. This should be avoided in our new production suite. The already available numerical algorithms and implementations will be extended in order to tackle large organic metal complexes in a solvent or specific molecular environment. By this it is intended to support material science in the development of efficient OLEDs. Additionally, far-reaching opportunities for scientific cooperations with experimentally working groups are planned to make the project most fruitful.

有机电子学以其广泛的适用性和低能耗成为未来的关键技术之一。与用固态物理方法描述的半导体器件不同，有机电子学是基于分子结构的，需要不同的量子化学方法。在这两种情况下，对数值的要求都非常高，需要开发有效的理论方法，以便获得深刻的见解并跟上技术进步的步伐。在这个项目中，我们将重点放在含有重金属过渡金属的有机三重态发射体上，它们表现出非常高的量子产额。这种高效率可以通过提供导致每个注入到材料中的电子/空穴对几乎完全复合的机制来实现。这种激子局限在发射中心，并显示出25%的单线态和75%的三线态的统计混合。三重态激子不是直接服从复合的，如果将重过渡金属引入络合物中，复合会发生很大的变化。因此，在强自旋轨道耦合(SOC)的存在下，三重态也能非常有效地复合。因此，在设计新的高效三重态发射体时，必须准确描述由于引入重原子而引起的所有影响，包括电子关联和环境。我们小组开发了一种理想的方法来实现这一点，该方法是基于完全相对论的极化传播子。到目前为止，应用的方法往往引入SOC的近似处理，或者在处理过程中相当复杂。在我们的新生产套件中应该避免这种情况。已有的数值算法和实现将被扩展，以处理在溶剂或特定分子环境中的大的有机金属络合物。这样做的目的是为了支持材料科学开发高效的OLED。此外，还计划提供与实验工作组进行科学合作的深远机会，以使该项目最富有成效。