A novel spiro-annulated host based on carbazole with good thermal stability and high triplet energy for efficient blue and green phosphorescent organic light-emitting diodes

• A novel spiro-annulated host based on carbazole has been synthesized and characterized.
• The dye exhibits good thermal stability and high triplet energy.
• Efficient blue and green phosphorescent organic light-emitting diodes based on the dye have been fabricated.

A novel spiro-annulated host based on carbazole was synthesized and fully characterized. The thermal, photophysical and electrochemical properties of this host material were investigated. The host exhibited good thermal stabilities with a decomposition temperature of 427 °C and also exhibited excellent morphological properties. A high triplet energy (2.90 eV) was obtained for the host due to its spiro-annulated structure. This host was proved to be effective for both blue and green phosphorescent organic light-emitting diodes. Four different blue devices were fabricated with the best performance that a maximum current efficiency of 12.2 cd A−1 and a maximum power efficiency of 8.8 lm W−1. The performance of the host was better than that of 4,4′-bis(9-carbazolyl)-biphenyl which is the benchmark host material in green PHOLED devices.

A novel spiro-annulated host material (H2) based on carbazole for efficient blue and green phosphorescent organic light-emitting diodes was synthesized and characterized. The devices based on H2 exhibit excellent performance due to its high triplet energy (2.90 eV) and good thermal stability. Four different blue devices were fabricated with the best performance of a maximum current efficiency of 12.2 cd A−1 and a maximum power efficiency of 8.8 lm W−1. The performance of H2 was better than that of 4,4′-bis(9-carbazolyl)-biphenyl (CBP) which is a star host material in green devices.Figure optionsDownload as PowerPoint slide