Enhanced pure red light-emitting devices advance wearable technology

Enhanced pure red light-emitting devices advance wearable technology
by Riko Seibo
Tokyo, Japan (SPX) May 08, 2024

The research team led by Professor Jiwoong Yang at DGIST, in collaboration with Professor Moon Kee Choi's team from UNIST, has made significant advances in wearable display technology by developing high-efficiency, skin-attachable perovskite pure red light-emitting devices. This innovation, achieved through selective surface modification of perovskite quantum dots, promises enhanced performance and broader application in wearable technologies.

The use of perovskites, known for their potential in solar cells and light-emitting devices, has been extended to wearable displays, driven by their cost-effectiveness and superior light-emission properties. Traditionally, the instability and inferior electrical properties of red perovskite materials limited their use in high-performance applications. However, by modifying the surface of perovskite light-emitting layers, the DGIST-UNIST research team has significantly enhanced their stability and electrical performance.

This breakthrough was accomplished by substituting iodine in the surface treatment process with bromine, which offers a higher electronegativity and enlarges the perovskite structures, thereby improving the surface-to-volume ratio and maintaining the band gap energy. These modifications have led to the development of devices with notable stability and an external quantum efficiency of up to 19.8%.

Professor Jiwoong Yang remarked, "By selectively modifying the surface of perovskite quantum dots, we improved their stability and electrical properties, ultimately achieving an external quantum efficiency (EQE) of up to 19.8%. This research brings us closer to the commercialization of pure red perovskite displays." Adding to this, Professor Moon Kee Choi stated, "The newly developed light-emitting devices are expected to be widely applied not only in perovskite LED-based displays but also in VR, AR, and smart wearable device development."

This research received support from the Ministry of Science and ICT, the National Research Foundation of Korea, and the Pohang Accelerator Laboratory. The findings were published in the prestigious journal "Materials Today."

Research Report:Highly efficient pure red light-emitting diodes through surface bromination of CsPbI3 perovskite nanocrystals for skin-attachable displays