Breakthrough: Ultra-High Efficiency Perovskite LEDs Developed by Researchers

The development of The Lads involved strengthening the perovskite lattice and suppressing the material's inherent low-frequency dynamics. Perovskite light emitters have gained attention as promising next-generation emitters due to their excellent color purity, tunability, and cost-effectiveness.

Prior to 2014, perovskites were mainly used in solar cells as their luminescence was not bright enough to be visible at room temperature. However, Professor Tae-Woo Lee recognized the potential of perovskite as a next-generation emitter early on and secured fundamental patents for perovskite light-emitting materials in 2014. In 2015, his team published a research paper demonstrating the enhancement of efficiency in perovskite LEDs from 0.1% to 8.53%, comparable to phosphorescent OLEDs, inspiring researchers worldwide to conduct further research.

Professor Lee's team made significant advancements in perovskite self-emissive devices in 2022, achieving an external quantum efficiency (EQE) of 28.9%, peak brightness of 470,000 nits, and an operational lifetime of up to 30,000 hours. His startup company, SN Display Co. Ltd., showcased TV and tablet display prototypes at CES in 2022 and 2023, moving closer to commercialization.

Addressing a key challenge, the research team focused on reducing luminescence efficiency due to the inherent ionic nature of perovskite. Perovskite materials, unlike traditional inorganic semiconductors, are composed of weak ionic bonds, leading to dynamic disorder that interferes with the radiative recombination process. Collaborating with other experts, Professor Lee's team proposed a mechanism using conjugated molecular multipods (CMMs) to enhance luminescence efficiency.

The incorporation of CMMs strengthens the perovskite lattice, suppressing low-frequency dynamics and reducing dynamic disorder, ultimately improving luminescence efficiency. This breakthrough led to the development of ultra-high-efficiency LEDs with an EQE of 26.1%, a significant achievement in perovskite nanocrystal LEDs.

Recognized for their high potential as next-generation display emitters, the perovskite emitters developed by Professor Lee's team exhibit high color purity and efficiency, particularly in the green spectrum crucial for ultra-high-definition displays. The research team's LEDs approach the green primary color in the Rec. 2020 standard, accelerating the commercialization of next-generation displays.

Professor Tae-Woo Lee expressed, "This research offers a material-based approach to overcoming the intrinsic limitations of perovskite light emitters, contributing to the development of high-efficiency, long-lifetime devices and the commercialization of next-generation displays." Professor Andrew M. Rappe added, "By combining molecular chemistry, physics, mechanics, and optics, we are inventing new materials for a bright and energy-efficient future."

Paper: Read the full paper here