Recent advances in OLED applications of TADF materials with decreased singlet-triplet energy gaps

Abstract

Thermally activated delayed fluorescence (TADF) has emerged as a paradigm-shifting strategy in the framework of organic light-emitting diode (OLED) technology by enabling almost 100% internal quantum efficiency due to the utilization of both singlet and triplet excitons. This review will critically discuss recent progress on molecular design for the development of TADF materials, their integration into diverse OLED architectures, and the challenges that limit their commercial translation. Key molecular strategies leading to excited-state dynamics control and suppression of efficiency roll-off include donor-acceptor engineering, rigidification, multiple resonance structures, and through-space charge transfer. On the other hand, key optimizations at the device level, includes the host-guest interactions, charge/exciton balance, and stability enhancement. Finally, the focus is shifted towards emerging trends such as room temperature phosphorescence-TADF hybrids, circularly polarized TADF, and AI-guided TADF discovery to guide the next generation of high-performance, stable, and color-pure OLEDs. © 2026 Elsevier B.V.