Manipulating backbone structure with various conjugated spacers to enhance photovoltaic performance of D–A-type two-dimensional copolymers

Abstract

a b s t r a c tA class of low band-gap two-dimensional conjugated polymers of PBDTT-FQ, PBDTT-TQ, PBDTT-BTQ and PBDTT-TTQ was designed and synthesized, which contains the same di(alkylthiophene)-substituted benzo [1,2-b:4,5-b 0 ]dithiophene (BDTT) and 6,7-difluoroquinoxaline (Q) units, as well as various conjugated spacers of furan, thiophene, bithiophene and thieno [3,2-b]thiophene in the main chain. Significant effect of the varied spacers between the BDTT and Q units on the thermal, optical, electrochemical and photovoltaic properties was investigated and observed for these two-dimensional copolymers in the polymer solar cells. The maximum power conversion efficiency of 5.9% with a short circuit current of 13.7 mA/cm 2 and a fill factor of 0.56 was obtained for the PBDTT-TQ with thiophene spacer in the bulk hetero-junction PSCs using [6,6]-phenyl-C 71 -butyric acid methyl ester as acceptor.

Improved photovoltaic performance of a 2D-conjugated benzodithiophene-based polymer by the side chain engineering of quinoxaline

“…29 Furthermore, to explore the interactions between the BDT-T and 5,8dithienylquinoxaline (DTQx) in polymers, there are some exciting reports about the BDT-T-alt-DTQx-based polymers recently. [30][31][32][33][34] For instance, Hou et al reported a polymer of PBDTDTQx-T with an alternating D-A backbone of BDT-T-alt-2,3-di(3-alkyloxyphenyl)-DTQx. 32 To further study the effect of various substituted side chains on the photovoltaic properties of these BDT-T-alt-DTQx polymers, our group recently reported two other polymers of PBDTT-TQ with an alternating D-A backbone of BDT-T-alt-6,7-difluoro-2,3-di(3-alkyloxyphenyl)-DTQx and PBDTDT(Qx-2)-T with an alternating D-A backbone of BDTT-alt-6,7-dialkyloxy-2,3-di(4-alkyloxyphenyl)-DTQx, 33,34 respectively.…”

Preparation and Characterization of Quinoxaline-Pyrene-Based Conjugated Copolymers for Organic Photovoltaic Devices

“…The preparation of M1, M2, and M3 was performed according to literature procedures [24,[31][32][33][34]. As shown in Scheme 1, PPyQxff and PPyQx were developed via Stille coupling polymerizations in moderate yields using a palladium (II) acetate/tri(o-tolyl) phosphine catalytic system.…”

Synthesis of Alternating Low‐Bandgap Conjugated Polymers Based on Dithieno[2,3‐d:2′,3′‐d′]naphtho[1,2‐b:3,4‐b′]dithiophene and Enhancement of Photovoltaic Properties with Solvent Additives

“…The general synthetic route toward the polymers is outlined in Scheme . 2,7‐Bis(trimethyl‐stannyl)‐10,11‐di(3,7‐dimethyloctyloxy)dithieno[2,3‐ d :2′,3′‐ d ′]naphtho[1,2‐ b :3,4‐ b ′]dithioph‐ ene (I), DBrID, and 3,6‐bis(5‐bromo‐ thieno‐2‐yl)‐ N , N ′‐bis(2‐hexyldecyl)‐1,4‐dioxopyrrolo[3,4‐ c ]pyrrole (DBrDPP) were synthesized as the procedures reported in the references. The structures of the monomers were confirmed by 1 H NMR and elemental analyses before use.…”