Creating a Molecular‐scale Graded Electronic Profile in a Single Polymer to Facilitate Hole Injection for Efficient Blue Electroluminescence

Graded electronic profile in single polymer can be established by grafting dual hole-transporting groups onto the polymer structure with finely adjusted spatial and energetic sequence among them. Light emitting devices based on these materials exhibit external quantum efficiencies of 4.54% and 7.53% for deep blue and blue emitting devices, respectively. The present efficiencies for devices with merely simple sandwich structures challenge other polymer-based blue devices to date.