Tuning the Polarizability in Donor Polymers with a Thiophenesaccharin Unit for Organic Photovoltaic Applications. (18th February 2014)

• Record Type: Journal Article
• Authors: Xu, Tao; Lu, Luyao; Zheng, Tianyue; Szarko, Jodi M.; Schneider, Alexander; Chen, Lin X.; Yu, Luping
• Is Part Of: Advanced functional materials. Volume 24:Number 22(2014)
• Page Start: 3432
• Page End: 3437
• Publication Date: 2014-02-18
• Subjects: Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201303688
• Languages: English
• ISSNs: 1616-301X

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>This paper describes the synthesis of low bandgap copolymers incorporating an artificial sweetener derivative, <italic>N</italic>‐alkyl, 3‐oxothieno[3, 4‐<italic>d</italic>]isothiazole 1, 1‐dioxide (TID). This new TID unit is identical to the well‐known thieno[3, 4‐<italic>c</italic>]pyrrole‐4, 6‐dione (TPD) unit except that one carbonyl has been replaced by a sulfonyl group. Semi‐empirical calculations on the local dipole moment change between ground and excited states (Δμ_ge) in the repeating units of the new polymer indicate that the replacement of the carbonyl by a sulfonyl group leads to larger Δμ_ge values. The resulting polymers exhibit a diminished power‐conversion efficiency (PCE) compared to a bulk heterojunction (BHJ) solar cells with PC₇₁BM as an acceptor, which extends the correlation between PCE and Δμ_ge of single repeating units in p‐type polymers to a new regime. Detailed studies show that the strongly electron‐withdrawing sulfonyl group is detrimental to charge separation in alternating copolymers containing a TID unit.</p> </abstract>