title: Towards Monodisperse Star-Shaped Ladder-Type Conjugated Systems: Design, Synthesis, Stabilized Blue Electroluminescence, and Amplified Spontaneous Emission.
abstract: A novel series of monodisperse star-shaped ladder-type oligo(p-phenylene)s, named as TrL-n (n=1-3), have been explored. Their thermal and electrochemical properties, fluorescence transients, photoluminescence quantum yields, density functional theory calculations, electroluminescence (EL) and amplified spontaneous emission (ASE) properties have been systematically investigated to unravel the molecular design on optoelectronic properties. The resulting materials showed excellent structural perfection, free of chemical defects, and exhibited great thermal stability (Td: 404-418 °C and Tg: 147-184 °C) and amorphous glassy morphologies. Compared with their corresponding linear counterparts FL-m (m=1-3), TrL-n showed only little bathochromic shifts (5-12 nm) for the absorption maxima λmaxin both solution and films. The star-shaped ladder-type compounds exhibited enhanced optical stability and suppressed low-energy emission. Their EL spectra exhibited excellent stability with increasing the driving voltage from 6 to 12 V. Moreover, superior low ASE thresholds were recorded for TrL-n compared with FL-m. Rather low ASE threshold (29 nJ per pulse or 1.60 μJ cm-2) was recorded for TrL-3, demonstrating their promising potential as excellent gain media. This study provides a novel design concept to develop monodisperse star-shaped ladder-type materials with excellent structural perfection, which are vital for shedding light on exploring robust organic emitters for optoelectronic applications.
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Fang
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Si-Ju
authors.initials: SJ
authors.lastname: Chang
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Jin-Jin
authors.initials: JJ
authors.lastname: Huang
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Shuang-Quan
authors.initials: SQ
authors.lastname: Chu
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Shan-Ming
authors.initials: SM
authors.lastname: Hu
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Cheng-Fang
authors.initials: CF
authors.lastname: Liu
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China.|Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced, Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, 211816, China.
authors.forename: Wen-Yong
authors.identifier: http://orcid.org/0000-0003-2381-1570
authors.initials: WY
authors.lastname: Lai
authors.affiliation: Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, 9 Wenyuan Road, Nanjing, 210023, China.|Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced, Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing, 211816, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
keywords: amplified spontaneous emission; conjugation; density functional calculations; electroluminescence; star-shaped ladder-type molecules