Fundamentally elastic quantum dot light-emitting diodes. Credit: Institute for Basic ScienceIntrinsically stretchable quantum dot-based light-emitting diodes achieved record-breaking performance.A team of South Korean researchers led by Professor KIM Dae-Hyeong of the Center for Nanoparticle Research within the Institute for Basic Science has pioneered a novel method to stretchable display screens. The group revealed the first advancement of fundamentally stretchable quantum dot light-emitting diodes (QLEDs). Improvements in Display TechnologyIn the rapidly evolving world of display innovations, the mission for producing intrinsically stretchable screens has been ongoing. Traditional display screens, constrained by rigid and inflexible components, have actually struggled to evolve beyond flexible ones.There has been a clear requirement for novel materials and gadget styles that can withstand considerable stretching while maintaining their performance, which is essential for applications including wearable and versatile interfacing technologies.Limitations of OLED and Advantages of QLEDThe majority of the flexible display screens on the market employ organic light-emitting diode (OLED) innovation, which uses natural materials as light-emitting elements. Nevertheless, OLED typically has downsides such as limited brightness and color pureness concerns. On the other hand, QLED screens offer outstanding color brightness, reproduction, and durability, making them a compelling option for customers who focus on these factors.Schematic illustration of is-QLED based on the inherently stretchable emission layer. The stretchable EML is a ternary composite of QDs, SEBS-g-MA, and TFB, with an unique internal structure of phase separation. The TFB-rich islands at the bottom of stretchable EML help with the hole injection into QDs while decreasing excitation satiating sites, thus boosting the gadgets effectiveness and brightness. Credit: Institute for Basic ScienceChallenges in Developing Flexible QLEDsHowever, the intrinsic difficulty for developing versatile QLED screens lies in the nature of quantum dots (QDs) themselves; as 0-D inorganic nanoparticles, they do not possess inherent stretchability. There have actually been some attempts to embed QDs within elastic materials to create a elastic and light-emitting composite material.A substantial obstacle encountered during this technique was the elastomers insulating properties, which hamper the effective injection of electrons and holes into the QDs, thereby reducing the gadgets electroluminescent efficiency.Breakthrough in Material EngineeringHence the IBS scientists had to develop developments to conquer these restrictions. Their work showcased the incorporation of a third product in the composite to boost carrier shipment to the QDs. A p-type semiconducting polymer, TFB, was used to enhance both the stretchability of the device and the performance of hole injection. Including TFB likewise enhanced the balance between the electron and hole injections.The fundamentally stretchable QLEDs have a gadget structure where all the layers were crafted to have an adequate level of stretchability. The stretchable QLEDs might be extended to 50% with consistent gadget efficiency. Likewise, a passive matrix and full-color QLEDs were demonstrated. Credit: Institute for Basic ScienceEnhanced Device Structure and PerformanceAn appealing element of the ternary nanocomposite movie was the unique internal structure displaying stage separation, where TFB-rich “islands” are formed at the base and QDs embedded in the SEBS-g-MA matrix lay on top of these islands. This unique structural arrangement minimizes exciton quenching websites and improves hole injection effectiveness, leading to optimum device performance.After mindful selection and engineering of these products, the IBS researchers attained QLEDs with high brightness (15,170 cd m-2), which is the highest among the stretchable LEDs, in addition to a low threshold voltage (3.2 V). When substantial force was applied to stretch the material, the gadget did not suffer damage even. Even when stretched up to 1.5 times, there was no considerable change in the range between the quantum dots inside the device. For instance, if a 20-inch QLED television is made with this gadget, this implies that the screen efficiency will stay the exact same even when pulled to a 30-inch size.Future Directions and Potential ApplicationsCo-first author Professor KIM Dong-chan discussed, “Our research group has actually also developed a high-resolution pattern technology that can be used to stretchable quantum dot light-emitting layers,” including, “By combining light-emitting products and pattern innovation, we demonstrated the potential of our gadget for RGB LEDs and complex applications like passive matrix ranges.”This research not just demonstrates the superior performance of QDs in elastic displays however also sets a new instructions for additional improving device performance. Future research study will concentrate on optimizing carrier injection performance and stretchability across all device layers. This finding lays a solid structure for the next generation is-QLED technology, promising a future where screen technologies are not simply flexible but genuinely stretchable, allowing brand-new kinds of wearable electronics and beyond.Reference: “Intrinsically elastic quantum dot light-emitting diodes” by Dong Chan Kim, Hyojin Seung, Jisu Yoo, Junhee Kim, Hyeon Hwa Song, Ji Su Kim, Yunho Kim, Kyunghoon Lee, Changsoon Choi, Dongjun Jung, Chansul Park, Hyeonjun Heo, Jiwoong Yang, Taeghwan Hyeon, Moon Kee Choi and Dae-Hyeong Kim, 15 April 2024, Nature Electronics.DOI: 10.1038/ s41928-024-01152-wThis research study has been conducted in cooperation with colleagues from Seoul National University, Ulsan National Institute of Science and Technology, and Daegu Gyeongbuk Institute of Science and Technology. It was published in Nature Electronics on April 16, 2024.
Credit: Institute for Basic ScienceIntrinsically stretchable quantum dot-based light-emitting diodes achieved record-breaking performance.A team of South Korean researchers led by Professor KIM Dae-Hyeong of the Center for Nanoparticle Research within the Institute for Basic Science has actually originated a novel technique to elastic displays. Including TFB also improved the balance in between the electron and hole injections.The fundamentally elastic QLEDs have a gadget structure where all the layers were crafted to have an enough level of stretchability. If a 20-inch QLED TV is made with this device, this means that the screen performance will stay the same even when pulled to a 30-inch size.Future Directions and Potential ApplicationsCo-first author Professor KIM Dong-chan explained, “Our research group has also established a high-resolution pattern innovation that can be used to stretchable quantum dot light-emitting layers,” including, “By combining light-emitting materials and pattern innovation, we showed the potential of our device for RGB LEDs and complex applications like passive matrix arrays.”This research study not only shows the exceptional performance of QDs in stretchable screens but likewise sets a brand-new direction for further improving gadget efficiency.
