TY - JOUR
T1 - Steric Poly(diarylfluorene-co-benzothiadiazole) for Efficient Amplified Spontaneous Emission and Polymer Light-Emitting Diodes
T2 - Benefit from Preventing Interchain Aggregation and Polaron Formation
AU - Bai, Lubing
AU - Sun, Chen
AU - Han, Yamin
AU - Wei, Chuanxin
AU - An, Xiang
AU - Sun, Lili
AU - Sun, Ning
AU - Yu, Mengna
AU - Zhang, Kangning
AU - Lin, Jinyi
AU - Xu, Man
AU - Xie, Linghai
AU - Ling, Haifeng
AU - Cabanillas-Gonzalez, Juan
AU - Song, Ling
AU - Hao, Xiaotao
AU - Huang, Wei
N1 - Publisher Copyright:
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/4/1
Y1 - 2020/4/1
N2 - The effect of introducing side-chain steric hindrance on the optoelectronic properties of the well-studied green light emitting polymer (poly(9,9-di-n-octylfluorene-alt-benzothiadiazole), F8BT) is investigated by means of replacing the 9,9-dioctylfluorene unit by two novel steric hindrance functionalized monomers, namely, poly(9,9-diarylfluorene-alt-benzothiadiazole) (FDFBT) and poly(9,9-diarylfluorene-4-carbazole-alt-benzothiadiazole) (FCzBT). Bathochromic shifts of the optical spectra concomitant with enhanced photoluminescence quantum yields and improved film morphologies are found on the novel copolymers compared to F8BT. Femtosecond transient absorption spectroscopy demonstrates how steric hindrance effect in the novel copolymers manifests into enhanced stimulated emission and longer excited state lifetimes, associated with the suppression of polaron formation, all these being favorable features for light amplifying applications. Consequently, random lasing emission is achieved in films based on these copolymers with a threshold of three times lower than that of F8BT (22.95 µJ cm−2 for F8BT; 6.36 µJ cm−2 for FDFBT and 8.44 µJ cm−2 for FCzBT). Polymer light-emitting diodes based on the novel copolymers exhibit performances comparable to the best reported on fluorene-based devices. All of these results manifest the great potential of these novel copolymers for the application in the field of light-emitting devices.
AB - The effect of introducing side-chain steric hindrance on the optoelectronic properties of the well-studied green light emitting polymer (poly(9,9-di-n-octylfluorene-alt-benzothiadiazole), F8BT) is investigated by means of replacing the 9,9-dioctylfluorene unit by two novel steric hindrance functionalized monomers, namely, poly(9,9-diarylfluorene-alt-benzothiadiazole) (FDFBT) and poly(9,9-diarylfluorene-4-carbazole-alt-benzothiadiazole) (FCzBT). Bathochromic shifts of the optical spectra concomitant with enhanced photoluminescence quantum yields and improved film morphologies are found on the novel copolymers compared to F8BT. Femtosecond transient absorption spectroscopy demonstrates how steric hindrance effect in the novel copolymers manifests into enhanced stimulated emission and longer excited state lifetimes, associated with the suppression of polaron formation, all these being favorable features for light amplifying applications. Consequently, random lasing emission is achieved in films based on these copolymers with a threshold of three times lower than that of F8BT (22.95 µJ cm−2 for F8BT; 6.36 µJ cm−2 for FDFBT and 8.44 µJ cm−2 for FCzBT). Polymer light-emitting diodes based on the novel copolymers exhibit performances comparable to the best reported on fluorene-based devices. All of these results manifest the great potential of these novel copolymers for the application in the field of light-emitting devices.
KW - amplified spontaneous emission
KW - polaron formation
KW - poly(diarylfluorene-co-benzothiadiazole)
KW - polymer light-emitting diodes
KW - robust emission
UR - http://www.scopus.com/inward/record.url?scp=85078618701&partnerID=8YFLogxK
U2 - 10.1002/adom.201901616
DO - 10.1002/adom.201901616
M3 - 文章
AN - SCOPUS:85078618701
SN - 2195-1071
VL - 8
JO - Advanced Optical Materials
JF - Advanced Optical Materials
IS - 7
M1 - 1901616
ER -