Strategic Dihedral Angle Engineering for High-Efficiency Through-Space Charge Transfer TADF Emitters

• • D-A dihedral angles below 25° and interfragment distances within 4 Å are established as geometric criteria for high-efficiency TSCT-TADF emitters, validated by both theoretical predictions and experimental evidence. • • The newly designed molecular libraries, using DPXZ donor and QAO acceptor with benzene or carbazole bridges, achieve predicted delayed fluorescence efficiencies up to 96% and an average of 70% in thin film systems. • • The study integrates first-principles calculations, energy decomposition analysis, and statistical modeling across 24 experimentally reported and 54 newly designed TADF molecules, providing a robust theoretical framework for molecular design. • • The rational design strategy based on sub-25° D-A dihedral angles directly addresses the bottleneck of balancing small ΔE_ST and high oscillator strength, enabling efficient triplet harvesting and high PLQY in OLEDs.