Tetraphenylsilane-Based High Triplet Energy Host Materials for Blue Phosphorescent Organic Light-Emitting Diodes

A high triplet energy host material based on a tetraphenylsilane core, (4-((4-(9H-carbazol-9-yl)phenyl)diphenylsil)phenyl)-diphenylphosphine oxide (TSPC), was synthesized as the bipolar host material for blue phosphorescent organic light-emitting diodes (PHOLEDs). A diphenylphosphine oxide group and a carbazole group were attached to the tetraphenylsilane core to improve the hole and electron transport properties while keeping the high triplet energy of the core structure. TSPC was effective as the host material for blue PHOLEDs, achieving a high external quantum efficiency of 22.0% with a color coordinate of (0.14, 0.18).