Tuning the Polarizability in Donor Polymers with a Thiophenesaccharin Unit for Organic Photovoltaic Applications |
| |
| Authors: | Tao Xu Luyao Lu Tianyue Zheng Jodi M. Szarko Alexander Schneider Lin X. Chen Luping Yu |
| |
| Affiliation: | 1. Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois, USA;2. Department of Chemistry, Northwestern University, Evanston, Illinois, USA;3. Chemical Science and Engineering Division, Argonne National Laboratory, Lemont, Illinois, USA |
| |
| Abstract: | This paper describes the synthesis of low bandgap copolymers incorporating an artificial sweetener derivative, N‐alkyl, 3‐oxothieno[3,4‐d]isothiazole 1,1‐dioxide (TID). This new TID unit is identical to the well‐known thieno[3,4‐c]pyrrole‐4,6‐dione (TPD) unit except that one carbonyl has been replaced by a sulfonyl group.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 (Δμge) in the repeating units of the new polymer indicate that the replacement of the carbonyl by a sulfonyl group leads to larger Δμge 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 Δμge 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. |
| |
| Keywords: | structure– property relationships low bandgap polymers polymers organic photovoltaics solar cells |
|
|
