Spectrally Independent and Wide-Angle Light Extraction of Organic Light Emitting Diodes with Randomly Disassembled Nanostructure

Abstract

Organic Light Emitting Diodes (OLEDs) have emerged as popular screen advancements in digital appliances, thanks to their unique characteristics such as self-emitting ability, transparency, true dark tone, and flexibility. In comparison to liquid crystal displays, OLED displays offer superior performance. Moreover, OLEDs are also a promising option for illuminating purposes. Although significant progress in enhancing the internal quantum efficiency (IQE) of OLEDs, achieving an external quantum efficiency that matches their full potential has proven challenging due to optical losses. This paper explores the utilization of Randomly Disassembled Nanostructures (RaDiNa) for light extraction in flexible OLEDs. The study confirms that the implementation of RaDiNa enhances light extraction efficiency, particularly at angles above the critical angle, leading to an increased external quantum efficiency (EQE). The application of a cured polydimethylsiloxane (PDMS) onto the substrate resulted in the RaDiNa-structured OLEDs demonstrating not only an extended viewing angle but also stable light emission across all angles, reinforcing the technology's value for high-quality display applications. These findings underscore RaDiNa's potential for significantly improving the efficiency of flexible OLEDs without altering the light emission spectrum based on the viewing angle.