AI & Quantum Chemistry Boost Blue OLED Efficiency Beyond 25% Limit

Researchers at the Institute of Transformative Bio-Molecules at Nagoya University and the Institute for Advanced Study at Kyushu University are addressing a longstanding challenge in display technology: the inefficiency of blue OLED pixels. Conventional fluorescent blue OLEDs are limited to 25% efficiency, a stark contrast to the nearly 100% internal quantum efficiency achieved by red and green pixels utilizing materials like iridium. This disparity arises because blue light demands higher excited-state energy, accelerating degradation in iridium-based blue emitters and prompting a search for alternative solutions. The team combined quantum chemistry with machine learning to identify new organic molecules, excluding boron, for thermally activated delayed fluorescence (TADF) pixels, systematically analyzing a virtual library of over 19,000 candidates.

A significant hurdle in TADF molecule design has been the reliance on boron-containing frameworks, which are often synthetically complex to create. Therefore, the team systematically explored “boron-free” 13-ring structures assembled from five- and six-membered rings, generating a virtual library exceeding 19,000 molecules. This approach yielded two synthesized molecules exhibiting vivid blue emission with narrow bandwidths and reaching photoluminescence quantum yields of 93-99% in thin films, indicating highly efficient light emission. One device, based on Cz-PAH-1, neared the blue-primary color standard for Rec. 2020 ultra-high-definition displays, while another, using Cz-PAH-2, achieved a maximum external quantum efficiency of 35.2%.

Recently, a collaborative team pursued vibrant, energy-efficient displays and achieved a new milestone in blue OLED technology. Researchers combined artificial intelligence with quantum chemistry to design molecules exceeding the 25% efficiency limit of conventional fluorescent blue pixels, a longstanding bottleneck in OLED performance. This work, published in Angewandte Chemie International Edition on July 21, 2026, details a streamlined process for identifying and synthesizing novel organic materials. The researchers emphasize that this integrated workflow promises to accelerate the discovery of future organic functional materials beyond OLED applications.