The progress of OLED technology continues. Researchers from the University of Turku in Finland and Cornell University in the United States have developed a theoretical model that suggests how the use of polaritons could lead to a significant increase in the brightness of OLED (Organic Light Emitting Diode) devices.
The study, published in the journal Physical Review Letters, opens new perspectives for improving the efficiency of these devices, widely used in smartphones, televisions and other electronic displays.
Overview of the study
The proposed model involves inserting the OLED device between two semi-transparent mirrors, creating an optical cavity. In this way, the OLED light emitters are coupled with the light confined inside the cavity, generating a new hybrid state of light and matter called a polariton. Polaritons are quasi-particles that combine the properties of photons (particles of light) and excitons (electronic excitations in matter).Study Overview and Improvement Map
The idea of using polaritons to improve the performance of OLEDs is not new, but this study stands out for its in-depth analysis of the theoretical limitations of this approach. The researchers identified the “sweet spot” where the polaritonic effect is maximum, finding that the efficiency of the process depends on the number of OLED molecules coupled to the optical cavity: the fewer molecules involved, the greater the polaritonic effect.
The theoretical results show significant potential. In one of the simulated scenarios, the conversion rate from electricity to light increased by as much as 10 million times thanks to the polaritonic effect. However, the authors point out that, as the number of molecules involved increases, the polaritonic effect tends to decrease. This means that, at the current state of the technology, it is not possible to achieve a significant improvement simply by adding mirrors to existing OLED devices.
Research is now focused on developing new architectures that allow for the efficient coupling of single molecules or groups of molecules to the optical cavity. Another promising avenue is the design of new OLED molecules specifically optimized for interaction with polaritons. The ultimate goal is to realize polariton OLED devices with significantly higher efficiency and brightness than traditional OLEDs, paving the way for next-generation displays with reduced power consumption and improved image quality.
And speaking of OLEDs, the production of high-performance displays will have a new hub in the USA with Japan Display.
