Synergetic Horizontal Dipole Orientation Induction for Highly Efficient and Spectral Stable Thermally Activated Delayed Fluorescence White Organic Light‐Emitting Diodes

• DOI: 10.1002/adfm.202203022
• Publication Date: 2022-04-28T12:36:46Z
• Authors: Xiaomei Peng; Weidong Qiu; Wenqi Li; Mengke Li; Wentao Xie; Wei Li; Jianying Lin; Jiaji Yang; Xin Li; Shi‐Jian Su
• Keywords: Quantum Efficiency

Abstract Radiative exciton generation and light out‐coupling are two crucial factors for highly efficient organic light‐emitting diodes (OLEDs). Herein, a thermally activated delayed fluorescence (TADF) material DspiroS‐TRZ with high horizontal dipole ratio (HDR, Θ // = 82%) is utilized as the blue emitter well host an orange‐red TADF TPA‐AQ to fabricate white OLEDs. A synergetic orientation induction on transition moment of achieved by orientated DspiroS‐TRZ, resulting in HDR (Θ 96%) emitter. Owing simultaneous triplet utilization binary system, maximum external quantum efficiency (EQE max ) 29.3% single emission layer (EML) OLED, excellent 34%. In addition, carrier recombination EML further regulated inserting regulation layer, which can relieve trapping effect guarantee stable Langevin energy transfer processes improved electroluminescence spectral stability. An EQE 31.2% ultimately double‐EML highlighting key role modulation