QL-Tex: Quantum dot based electroLuminescent Textiles

电致发光（EL）器件以其坚固而薄的显示元件而闻名，在环境照明领域中得到越来越多的关注。在过去的几年中，人们一直在努力将它们实施在基于纤维的基底上，以从纺织品的触觉和柔性中获益。一个令人兴奋的愿景纺织显示器的基础上交织发光灯丝驱动的研究活动。不幸的是，大面积EL发光器件仍然限于很少的颜色和总体低的光强度。更多的研究，例如，新的复合材料和设备架构需要提高其性能。我们的想法是探索胶体量子点（QD）在光发射器，特别是在交流驱动发光纺织品的应用。QD可以提供色域的受控扩展，并且另外增加光发射器的整体性能，如从对LED、OLED、QLED和LEC的研究中已知的。此外，已经表明，EL器件中QD的成功AC激发原则上是可能的。然而，基于QD的柔性和/或纤维基（纺织品）衬底上的大面积EL发光器件尚未得到证实。本计画将探讨胶体量子点作为活性发光材料应用于电激发光元件是否能提升其效能及扩大色彩范围，进而实现白色发光纺织品。因此，在第一步骤中，来自已建立的材料的蓝色和/或绿色EL发射将通过红色发光QD来实现，以获得白色光发射颜色。颜料和QD的混合比的受控变化将导致具有高显色值（CRI>80）和可控色温的平衡的白色发射。为此目的，QD应被并入介电层中或直接施加。除了技术上的挑战外，第二步还将研究EL器件中量子点的激发机制。我们的假设是，量子点与高-k的组合使用可以导致显着降低工作电压的EL纺织品和增加其强度。该项目的技术挑战只能在惰性气体手套箱系统的帮助下克服：所有制造步骤都在内部进行。应研究最佳器件设计，包括在受控气氛下在纺织品基底和长丝上溅射量子点和基于溶液的量子点沉积期间调整工艺参数。聚对二甲苯本身也可用作电介质，其对器件的封装也发生在手套箱系统内。最后，将研究和评估纺织照明器件的电光特性，然后调整材料系统，器件结构和制造工艺。

Electroluminescent (EL) devices, well-known as robust and thin display components, get increasing attention in the field of ambient lighting. Over the last years there have been efforts to implement them on fiber-based substrates to profit from the haptics and flexibility of textiles. An exciting vision of textile displays based on enmeshed light-emitting filaments drives the research activities. Unfortunately, large-area EL light-emitting devices are yet limited to few colors and overall low light intensity. More research, e.g., on new composite materials and device architectures is required to increase their performance. Our idea is to explore the application of colloidal quantum dots (QDs) in light emitters, especially in AC-driven luminescent textiles. QDs can provide a controlled expansion of the colour gamut and in addition increase the overall performance of the light-emitters, as already known from the research on LEDs, OLEDs, QLEDs and LECs. Furthermore, it was already shown, that a successful AC excitation of QDs in EL devices is principally possible. However, large-area EL light-emitting devices on flexible and/or fiber-based (textile) substrates based on QDs have not been demonstrated yet. This project will explore whether the application of colloidal QDs as an active luminescent material in EL devices can increase their performance and expand the color range, so that white luminescent textiles can be realized. Thereby in a first step blue and/or green EL emission from the established materials shall be accomplished by red-luminescent QDs to obtain a white light emission color. The controlled variation of the mixing ratios of pigments and QDs shall result in a balanced white emission with high color rendering values (CRI>80) and a controllable color temperature. For this purpose, the QDs shall be either incorporated into the dielectric layer or applied directly. In addition to the technological challenges, the excitation mechanism of the quantum dots within EL devices shall be investigated in the second step. Our hypothesis is that the use of QDs in combination with high-k dielectrics can lead to a significant reduction in the operating voltages of the EL textiles and increase of their intensity. The technological challenges of this project can only be overcome with the help of the inert gas glovebox system: all fabrication steps take place inside. The optimal device design shall be investigated, including the adjustment of process parameters during sputtering of the dielectrics and solution-based deposition of the QDs on textile substrates and filaments under controlled atmosphere. The encapsulation of the devices by parylene, which can also serve as a dielectric itself, takes place inside the glovebox system as well. Finally, the electro-optical properties of the textile lighting devices will be studied and evaluated, followed by adjustments of the material system, device architecture and fabrication processes.