Artificial light is essential to modern life, yet its growing demand significantly increases energy consumption and environmental impact. Organic light-emitting diodes (OLEDs) offer an attractive alternative to conventional semiconductor lighting technologies because they combine high efficiency with the potential for lightweight, flexible, and material-efficient fabrication. However, their wider deployment in lighting applications has been limited by intrinsic material challenges, including low electrical conductivity, sensitivity to environmental degradation, and efficiency losses at high operating power. As a result, current OLEDs remain largely confined to display technologies rather than large-scale lighting.
The PLAS-OLED project addressed this challenge by exploring whether the performance and stability limitations of OLEDs could be overcome by engineering their photonic environment. Specifically, the project investigated the integration of OLED emitters into optical microcavities that confine light and modify the interaction between emitted photons and molecular excitations. Under suitable conditions, this interaction leads to the formation of hybrid light–matter states known as polaritons.
The overall objective of PLAS-OLED was to determine whether polaritonic effects could be harnessed to improve the efficiency and spectral performance of OLEDs and white OLEDs (WOLEDs), while also enabling simplified device architectures based on single, more stable emitters. By controlling both the emission processes inside the device and the escape of photons from it, the project aimed to establish new strategies for achieving efficient light generation without relying on complex multi-emitter systems.
Over the course of the project, we demonstrated that polariton formation provides a viable pathway to selectively influence key emission processes in OLEDs. Importantly, our findings show that strong light–matter coupling does not universally enhance all radiative processes, but instead primarily affects inefficient recombination pathways and emission disperssion. This provides a realistic framework for using photonic design to suppress loss mechanisms and improve device operation. The project therefore concludes that polariton engineering represents a promising strategy for enhancing OLED performance while supporting the development of more stable and potentially lower-impact lighting technologies.
