Multi-resonance TADF materials for highly efficient and stable OLEDs

先进材料支撑着大多数现代技术，包括电子、通信、显示器、照明和太阳能电池。发光材料特别令人感兴趣，因为它们可用于照明、信息显示和激光。该项目的目的是开发高效、色纯、稳定的新型发光材料。当在被称为有机发光二极管（OLED）的设备中施加电压时，这些材料会发光。OLED被用于制作电视、移动的手机和智能手表屏幕，具有出色的对比度和鲜艳的色彩，可以从各种角度以及直视下清晰地观看。OLED也是一种重要的新兴照明技术。高效的OLED材料将减少能源消耗，从而有助于实现英国到2050年实现净零碳排放的宏伟目标。商业OLED材料可以提供高效的红色和绿色发射，但含有非常稀有和昂贵的金属，如铱;蓝色发光体的效率要低得多，因为它不含金属。新一代OLED材料通过称为热激活延迟荧光（TADF）的过程实现高效率，但通常具有宽发射光谱，导致颜色不是纯红色、绿色或蓝色，因此不满足对这些颜色的严格工业要求。我们将探索一种新兴的TADF材料，它通过使用所谓的“多共振”TADF结构来克服这些限制，这种结构更加刚性。这种刚性导致窄的发射光谱，因此颜色更纯，此外还提高了材料的稳定性，这是提高相应OLED稳定性的关键。利用我们最近在这一领域发表的工作，我们将联合收割机的见解，从化学和物理开发新的类MR-TADF发射器，使有效的红色，绿色和深蓝色的发射。我们将进一步提高OLED的效率，通过制造这些材料的一些第一个例子，这些材料以某种方式排列，使更多的光能够从器件中逸出。

Advanced materials underpin most modern technologies including electronics, communications, displays, lighting and solar cells. Light-emitting materials are of particular interest because they can be used for lighting, information display and lasers. The purpose of this project is to develop new light-emitting materials with high efficiency, purity of colour and stability. The materials will emit light when a voltage is applied to them in devices called organic light-emitting diodes (OLEDs). OLEDs are used to make television, mobile phone and smartwatch screens with excellent contrast and vivid colours, that can be viewed clearly from a wide array of angles as well as straight on. OLEDs are also an important emerging lighting technology. Efficient OLED materials will reduce energy consumption and so contribute to reaching the UK's ambitious target of net-zero carbon emissions by 2050.Commercial OLED materials can give efficient red and green emission but contain very rare and expensive metals such as iridium; the blue emitter is much less efficient as it does not contain the metal. A newer generation of OLED materials achieve high efficiency by a process called thermally activated delayed fluorescence (TADF), but usually have broad emission spectra, leading to colours that are not pure red, green or blue, and so do not satisfy the stringent industry requirement for these colours. We will explore an emerging class of TADF materials that overcomes these limitations by using so-called "multi-resonant" TADF structures that are much more rigid. This rigidity leads to narrow emission spectra and hence purer colours, and in addition improves the stability of the materials, which is key to improving the stability of the corresponding OLEDs. Capitalizing on our recent published work in this area, we will combine insights from chemistry and physics to develop new classes of MR-TADF emitters that give efficient red, green and deep blue emission. We will further enhance the efficiency of OLEDs by making some of the first examples of these materials that are aligned in a way to enable more light to escape from the devices.