Advances in Flexible, Foldable, and Stretchable Quantum Dot Light-Emitting Diodes: Materials and Fabrication Strategies

Abstract

Deformable light-emitting devices, capable of maintaining consistent light emission even under mechanical deformations, represent a cornerstone for next-generation human-centric electronics. Quantum dot light-emitting diodes (QLEDs), leveraging the electroluminescence (EL) of colloidal quantum dots (QDs), show exceptional promise in this domain. Their superior advantages, such as excellent color purity, high luminous efficiency, slim form factor, and facile fabrication on various soft substrates, position them as prime candidates for deformable EL devices. This review explores recent advancements in deformable QLEDs, with a particular focus on material engineering and fabrication strategies. We begin by introducing various types of QDs and the operational principles of QLEDs, along with summarizing performance enhancements in reported deformable devices. Next, we categorize device structures based on the direction of light emission. We then discuss representative methods for patterning QD thin films on flexible substrates to fabricate full-color QLEDs. Additionally, we highlight fabrication strategies for deformable QLEDs with unconventional form factors, including flexible, foldable, fiber-type, and stretchable devices, and their potential applications. We conclude this review with a brief outlook on the future of this technology. © The Author(s), under exclusive licence to Korean Institute of Chemical Engineers, Seoul, Korea 2024.