Enabling a bright orange–red emission with a high EQE with a seven-member-ring based fluorescent emitter with a matching host

Highly efficient and stable pure-red phosphorescent organic light-emitting diodes based on heptacyclic bipolar hosts featuring an armor-like structure

“…Jou et al constructed OLED devices using organic molecules based on a heptacyclic structure, with an emission peak of 617 nm and an EQE of 7.2% at a luminescence intensity of 25 000 cd m −2 . 16 Therefore, the good stability and charge transport characteristics indicate the potential of the heptacyclic structure in the luminescent material, which is promising to effectively improve the stability of the material coupled with ensuring a certain EQE.…”