An indenocarbazole-based host material for solution processable green phosphorescent organic light emitting diodes. Issue 47 (1st September 2021)

• Record Type: Journal Article
• Authors: Park, Eun Young; Lee, Da Hwan; Le, Thi Na; Shin, Chol-Min; Lee, Jihoon; Suh, Min Chul
• Is Part Of: RSC advances. Volume 11:Issue 47(2021)
• Page Start: 29115
• Page End: 29123
• Publication Date: 2021-09-01
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d1ra04855d
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : We designed and synthesized a new host material with a highly soluble and thermally stable indenocarbazole derivative that can make green phosphorescent organic light-emitting diodes (PHOLEDs) in a solution process. Abstract : We designed and synthesized a new host material with a highly soluble and thermally stable indenocarbazole derivative (7, 7-dimethyl-5-phenyl-2-(9-phenyl-9 H -carbazol-3-yl)-5, 7-dihydro-indeno[2, 1- b ]carbazole) that can make green phosphorescent organic light-emitting diodes (PHOLEDs) in a solution process. In particular, these are used in a blue common layer structure in which green and red-emitting layers are formed by a solution process and blue common layers are thermally evaporated. The new host material possesses excellent hole transport capability and high triplet energy (T1 ). Mainly we designed the hole dominant material to keep the exciton forming area away from the hole transport layer (HTL) and emitting layer (EML) interface, an interfacial mixing area to improve device performance. As a result, the greatest lifetime of 1300 hours was achieved and a high current efficiency of up to 66.3 cd A −1 was recorded when we used the optimized device structure of a 5 nm thick bipolar exciton blocking layer (B-EBL). It may be a good agreement of exciton confinement and reduced electron accumulation at the HTL and EML interface.