High-performance light-emitting diodes based on carbene-metal-amides

Organic light-emitting diodes (OLEDs) promise highly efficient lighting and display technologies. We introduce a new class of linear donor-bridge-acceptor light-emitting molecules, which enable solution-processed OLEDs with near-100% internal quantum efficiency at high brightness. Key to this performance is their rapid and efficient utilization of triplet states. Using time-resolved spectroscopy, we establish that luminescence via triplets occurs within 350 nanoseconds at ambient temperature, after reverse intersystem crossing to singlets. We find that molecular geometries exist at which the singlet-triplet energy gap (exchange energy) is close to zero, so that rapid interconversion is possible. Calculations…

• RS
  Royal Society

  Awards: UF130278, award305185
• AO
  Academy of Finland

  Awards: award305189, Project 251448
• EA
  Engineering and Physical Sciences Research Council

  Award: EP/M005143/1
• ER
  European Research Council

  Awards: 338944, award300943