<i>ortho‐, meta‐</i>, and <i>para</i>‐Dihydroindenofluorene Derivatives as Host Materials for Phosphorescent OLEDs

Abstract

Abstract This work reports the first structure–properties relationship study of ortho [2,1‐ c ]‐, meta [1,2‐ a ]‐, and para [1,2‐ b ]dihydroindenofluorenes, highlighting the influence of bridge rigidification on the electronic properties. This study has made it possible to devise an extended π‐conjugated molecule with both a high triplet state energy level and excellent thermal and morphological stability. As a proof of concept, dihydroindenofluorenes were used as the host in sky‐blue phosphorescent organic light‐emitting diodes (PhOLEDs) w ith high performance.