Effects of sub-wavelength photonic nanostructures on thermally-activated delayed fluorescence

亚波长光子纳米结构对热激活延迟荧光的影响

• 批准号: EP/Y021495/1
• 负责人: Jean Charles Ribierre
• 金额: $ 104.52万
• 依托单位: University of St Andrews
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FY021495%2F1
• 关键词: Effects; sub; wavelength; photonic; nanostructures

Organic light-emitting diodes (OLEDs) have become a dominant technology in the display industry and hold great promise for a variety of applications in the fields of lighting, visible communication, sensing and healthcare. Current research efforts focus on the development of thermally-activated delayed fluorescent (TADF) emitters that promise highly efficient and long-lifetime performance without the use of any heavy metals. These materials show a small energy gap between their singlet and triplet energy levels allowing the up-conversion of non-emissive triplets to light-emitting singlets at room temperature via the reverse intersystem crossing process. Although efficient triplet harvesting can take place in TADF OLEDs, the dynamics involved in the TADF mechanism need to be faster to substantially reduce the accumulation of long-lived triplet excitons during the device operation and improve their overall performance. This project addresses this research challenge by proposing an innovative approach based on the integration of sub-wavelength photonic nanostructures into TADF OLEDs. Via their effects on the local photonic density and the dielectric permittivity of the effective media, the photonic nanostructures will be engineered to accelerate both radiative decay and reverse intersystem crossing rates. This will improve the efficiency of OLEDs, especially at high brightness and increase their lifetime. The successful outcome of the project is expected to lead to an improvement of the TADF OLED technology and will be highly relevant for a range of other applications in fields as diverse as organic optoelectronics, sensing and photochemistry.

有机发光二极管（OLED）已成为显示行业的主导技术，并在照明、可见光通信、传感和医疗保健等领域的各种应用中具有广阔的前景。目前的研究工作集中在热激活延迟荧光（TADF）发射器的开发上，该发射器有望在不使用任何重金属的情况下实现高效和长寿命的性能。这些材料在单线态和三线态能级之间显示出较小的能隙，从而允许在室温下通过反向系间窜越过程将非发射三线态上转换为发光单线态。尽管 TADF OLED 可以实现高效的三重态捕获，但 TADF 机制中涉及的动力学需要更快，才能大幅减少器件运行期间长寿命三重态激子的积累，并提高其整体性能。该项目通过提出一种基于将亚波长光子纳米结构集成到 TADF OLED 中的创新方法来应对这一研究挑战。通过对有效介质的局部光子密度和介电常数的影响，光子纳米结构将被设计为加速辐射衰减和反向系间交叉速率。这将提高 OLED 的效率，尤其是在高亮度下，并延长其使用寿命。该项目的成功预计将促进 TADF OLED 技术的改进，并将与有机光电子、传感和光化学等领域的一系列其他应用高度相关。