In:
Polymer International, Wiley, Vol. 66, No. 8 ( 2017-08), p. 1206-1213
Abstract:
A new series of conjugated copolymers ( PBDT‐TPD , PBDT ‐Th‐ TPD , PBDT‐TT‐TPD ) containing donor–acceptor (D − A) structure electron‐rich benzo[1,2‐ b :4,5‐ b ′]dithiophene ( BDT ) units with branched alkyl thiophene side chains and electron‐deficient 5‐(2‐octyl)‐4 H ‐thieno[3,4‐ c ]pyrrole‐4,6(5 H )‐dione (TPD) units was designed and synthesized. To tune the optical and electrochemical properties of the copolymers, the conjugation length of the copolymers was extended by introducing π‐conjugated spacers such as thiophene and thieno[3,2‐ b ]thiophene units. It was observed that PBDT‐TPD showed broader absorption spectra in the longer wavelength region and the absorption maximum was red‐shifted compared to that of PBDT‐Th‐TPD, PBDT‐TT‐TPD. Stokes shifts were calculated to be 52 nm for PBDT‐TPD, 153 nm for PBDT‐Th‐TPD and 146 nm for PBDT‐TT‐TPD. Further, PBDT‐TPD exhibited a deeper highest occupied molecular orbital energy level of −5.53 eV as calculated by cyclic voltammetry. Bulk heterojunction solar cells fabricated using PBDT‐TPD as donor material exhibited a power conversion efficiency of 1.92%. © 2017 Society of Chemical Industry
Type of Medium:
Online Resource
ISSN:
0959-8103
,
1097-0126
DOI:
10.1002/pi.2017.66.issue-8
Language:
English
Publisher:
Wiley
Publication Date:
2017
detail.hit.zdb_id:
2004753-8
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