Polyether containing N-[6-(N-carbazolyl)hexyl]carbazol-3-yl side chains and its model compound as components of organic light emitting diodes

Polyether containing electronically isolated carbazolyl fragments and its model compound were synthesized and characterized. Weight–average molecular weight of the polymer was 31,500 with polydispersity index of 2.4. Both the compounds represent amorphous materials of high thermal stability with glass transition temperatures of 137 °C for polymer and of 41 °C for model compound. The derivatives were tested as host materials in green as well as blue phosphorescent OLEDs. The green device with polymeric host exhibited turn-on voltage of 3.3 V, a maximal current efficiency of 11.5 cd/A and maximum brightness of 1312 cd/m2. An efficient blue OLED using the model compound as host demonstrated a turn-on voltage of ca. 4.3 V, a maximum brightness of 6225 cd/m2, and maximum current efficiency of 23.3 cd/A at 100 cd/m2.

► Derivatives with electronically isolated carbazolyl fragments were synthesized.
► The compounds were tested as host materials in blue OLEDs.
► Efficiency of 23 cd/A and brightness exceeding 6200 cd/m2 were obtained.