Highly Efficient Deep‐Blue Electrophosphorescence Enabled by Solution‐Processed Bipolar Tetraarylsilane Host with Both a High Triplet Energy and a High‐Lying HOMO Level

A new bipolar tetraarylsilane derivative with both a sufficiently high triplet energy and a high-lying highest occupied molecular orbital energy level is presented as an excellent host for the deep-blue phosphor. A solution-processed FIr6-based deep-blue phosphorescent organic light-emitting diode (PhOLED) is realized with high efficiency and low efficiency roll-off. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.