Double Layer Transfer Printing for High-Definition and Highly Efficient Quantum Dot Light-Emitting Diodes

As the demand for next-generation free-form electronic devices grows, there is an increasing need for displays that are not only highly efficient and high-definition but also flexible and deformable. Quantum dot (QD) light-emitting diodes (QLEDs) have emerged as a promising solution to meet these requirements. While QDs offer exceptional properties, such as high photoluminescence quantum yield, a broad color gamut, and excellent color purity, challenges remain in achieving high-definition QD patterning and efficient QLEDs.
In this presentation, we will explore advancements in high-definition, highly efficient QLEDs using a double-layer (DL) transfer printing of QD/ZnO films. This method, based on surface-engineered viscoelastic stamps, allows for the precise formation of red-green-blue pixelated patterns at an impressive 2,565 pixels per inch (PPI) and monochromatic QD patterns reaching an extraordinary ~20,526 PPI. The DL transfer printing technique ensures tight packing of QDs and ZnO nanoparticles, effectively reducing leakage current and significantly enhancing external quantum efficiency to 23.3%.
Additionally, we will showcase the fabrication of highly efficient, wearable QLEDs utilizing this innovative technique, emphasizing its potential in developing full-color QD electronic tattoos.