Hanyang University Team Develops World's Most Efficient Perovskite LED

Researchers at Hanyang University have achieved a significant milestone in display technology, developing a perovskite-based light-emitting diode (LED) that boasts world-leading luminous efficiency and color purity. This innovation, spearheaded by Professor Han Tae-hee's team at the Department of Materials Science and Engineering, addresses critical challenges that have previously hindered the widespread adoption of perovskite materials in next-generation displays.

The core of the breakthrough lies in a novel ligand exchange technology. Perovskite nanocrystals, while promising for their vibrant colors and high light-emission capabilities, have historically suffered from energy loss due to surface ligands impeding charge transport. Professor Han's team engineered a solution by precisely controlling the molecular structure on the nanocrystal surface. They developed a new technique that removes existing ligands and simultaneously binds multifunctional molecules with conjugated structures, which facilitate charge transport, thereby enhancing electrical connectivity between nanocrystals and optimizing charge flow.

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This research is a case where the charge balance, which determines the core performance of LED devices, is directly controlled not by external structure but by precisely designing the electronic properties of the nanocrystal surface.

This meticulous control over the nanocrystal surface chemistry has led to a remarkable achievement: an external quantum efficiency (EQE) of 31.7%. This figure represents the highest performance reported to date for perovskite nanocrystal LEDs, effectively solving the long-standing issue of charge imbalance. The implications are far-reaching, as this technology paves the way for more vivid and energy-efficient displays in virtual reality (VR), augmented reality (AR), wearable devices, and foldable screens.

Professor Han expressed optimism about the technology's potential, stating, "This research is a case where the charge balance, which determines the core performance of LED devices, is directly controlled not by external structure but by precisely designing the electronic properties of the nanocrystal surface." The successful development, published in the prestigious journal 'Advanced Materials,' signifies a major leap forward, positioning South Korea at the forefront of advanced display technology research and development. This achievement underscores the nation's commitment to innovation in high-tech industries.

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It is expected to become a technology that can be expanded to various optoelectronic devices and next-generation displays in the future.