A team of researchers has created full-color fiber light-emitting diodes (Fi-LEDs) by using perovskite quantum wires (PeQWs). This breakthrough could lead to the development of cutting-edge wearable lighting and display technologies.
A team of researchers from the School of Engineering at the Hong Kong University of Science and Technology (HKUST) has made full-color fiber light-emitting diodes that leverage perovskite quantum wires, which could revolutionize wearable lighting and display devices.
Fi-LEDs are a vital part of flexible LEDs due to their suitability for textile production and impressive spatial luminance uniformity. Metal halide perovskites (MHPs) have been identified as promising materials for future LEDs due to their excellent optoelectronic characteristics. However, making MHP-based Fi-LEDs has proven challenging because of issues like uneven coating caused by gravity and surface tension, poor crystallization quality, and complicated electrode application processes, which lead to inconsistent and ineffective light emission.
To address these challenges, the research team under the guidance of Prof. FAN Zhiyong, a Chair Professor at HKUST’s Department of Electronic & Computer Engineering and Department of Chemical & Biological Engineering, used an innovative technique involving porous alumina membrane (PAM) templates on thin aluminum fibers. They created the PAM with extremely small pores of about 5 nm using a roll-to-roll solution-coating method on aluminum fibers. They filled the MHP precursor solution into the PAM channels and then conducted a surrounding annealing process to guarantee even vaporization of solvents and crystallization of MHPs, facilitating the organized growth of PeQW arrays while reducing the chance of unwanted thin-film layers forming on the PAM’s surface.
The team successfully created full-color Fi-LEDs that emit light at peaks of 625 nm (red), 512 nm (green), and 490 nm (sky-blue). The produced fibers are flexible and stretchable, making them ideal for textile lighting applications. They also demonstrated various 2D and 3D designs, including a 2D full-color string that reads “I ♥ HKUST,” all showcasing excellent fluorescence uniformity. Furthermore, they produced a “night scene” of Victoria Harbor using PeQWs with color transitions induced by a halide gradient, showcasing both the adaptability and visual appeal of the Fi-LEDs.
This research marks a major leap forward in the Fi-LEDs domain. Future efforts could focus on improving the efficiency and durability of these light-emitting devices, investigating new compositions of perovskite for a wider array of emissions, and integrating these technologies into commercial textile products.
“The combination of the quantum confinement effect and the passivation from the 3D porous alumina membrane structure has allowed us to achieve remarkable photoluminescence and electroluminescence effectiveness. Our groundbreaking method for fiber LEDs opens new avenues for creating unconventional 3D-structured lighting sources and sets the stage for advanced wearable display technologies,” stated Prof. Fan.
