In:
Journal of Polymer Science Part A: Polymer Chemistry, Wiley, Vol. 54, No. 6 ( 2016-03-15), p. 771-784
Abstract:
Polymers using new electron‐deficient units, 2‐pyriminecarbonitrile and 2‐fluoropyrimidine, were synthesized and utilized for the photovoltaics. Donor‐acceptor (D‐A) types of conjugated polymers ( PBDTCN, PBDTTCN, PBDTF, and PBDTTF ) containing 4,8‐ bis (2‐octyldodecyloxy)benzo[1,2‐ b ;3,4‐ b′ ]dithiophene (BDT) or 4,8‐ bis (5‐(2‐octyldodecyloxy)thiophen‐2‐yl)benzo[1,2‐ b :4,5‐ b′ ]dithiophene (BDTT) as electron rich unit and 2‐pyriminecarbonitrile or 2‐fluoropyrimidine as electron deficient unit were synthesized. We designed pyrimidine derivatives in which strong electron‐withdrawing group (CN or fluorine) was introduced to the C2 position for the generation of strong electron‐deficient property. By the combination with the electron‐rich unit, the pyrimidines will provide low band gap polymers with low highest occupied molecular orbital (HOMO) energy levels for higher open‐circuit voltages ( V OC ). For the syntheses of the polymers, the electron‐rich and the electron‐deficient units were combined by Stille coupling reaction with Pd(0)‐catalyst. Absorption spectra of the thin films of PBDTTCN and PBDTTF with BDTT unit show shift to a longer wavelength region than PBDTCN and PBDTF with BDT unit. Four synthesized polymers provided low electrochemical bandgaps of 1.56 to 1.96 eV and deep HOMO energy levels between −5.67 and −5.14 eV. © 2015 The Authors. Journal of Polymer Science Part A: Polymer Chemistry Published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54 , 771–784
Type of Medium:
Online Resource
ISSN:
0887-624X
,
1099-0518
Language:
English
Publisher:
Wiley
Publication Date:
2016
detail.hit.zdb_id:
3004641-5
detail.hit.zdb_id:
1473076-5
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