Fused Perylene Diimide-Based Polymeric Acceptors for Efficient All-Polymer Solar Cells

Abstract

Two polymeric electron acceptors (PFPDI-2T and PFPDI-2FT) based on the fused perylene diimide (PDI) and bithiophene or difluorobithiophene units were synthesized via the Stille polymerization. Both polymers exhibit the strong absorption between 350 and 650 nm, which have the good absorption compensation with the low band gap conjugated polymer in polymer solar cells (PSCs). PFPDI-2T and PFPDI-2FT have the LUMO energy levels of around −4.12 to −4.15 eV, which are comparable with other PDI-based polymers and fullerene derivatives. All-polymer solar cells (all-PSCs) based on PFPDI-2T or PFPDI-2FT as the polymeric electron acceptor were fabricated with PTB7-Th as the polymeric electron donor. Power conversion efficiency of as high as 6.39% based on PFPDI-2T/PTB7-Th was achieved under the standard illumination of simulated sunlight (AM 1.5, 100 mW cm −2 ), which is significant higher than that of the all-PSC based on the nonfused PDI counterpart. The results demonstrate that the direct fusion of PDI unit is an effective design strategy to enhance the photovoltaic performances of all-PSCs.

Progress in the synthesis of perylene bisimide dyes

“…147,148 The Stille coupling between trans-1,2-bis(tributylstannyl)ethylene and bromo-substituted PBIs is of even greater synthetic importance as it gives access to vinylene-bridged oligomeric PBIs. The latter compounds represent the key building blocks in the synthesis of fused dimeric PBIs and PBI nanoribbons, 149 in addition to ethylenefused polymers, 150,151 although it should be pointed that the synthetic route for the preparation of the first ethynylene-fused dimeric PBI involved cyclization of alkyne-bridged PTE. 152 Ethenyl-bridged dimeric PBI 134 was synthesized in 88% yield by coupling of bromo-PBI 7g with 0.5 equivalent of 1,2-bis(tributylstannyl)ethylene, using Pd(PPh 3 ) 4 as a catalyst (Scheme 39).…”

Aromatic‐Diimide‐Based n‐Type Conjugated Polymers for All‐Polymer Solar Cell Applications

“…They designed a new acceptor based on FPDI and vinylene unit and achieved a high PCE of 8.59% when blending with PTB7‐Th, which indicated that FPDI was a promising acceptor unit for applications in all‐PSCs. Subsequently, Zhang and co‐workers investigated a series of n‐type polymers based on FPDI and different copolymerized units such as DT, ffDT, 4,7‐dithienyl‐2,1,3‐ benzothiadiazole (DTBT), BDT, T, TT, and Se . All‐PSCs fabricated with PTB7‐Th as the donor and these FPDI‐based polymers as acceptors exhibited remarkable PCEs of 5.35–6.58%.…”

Imide‐Functionalized Polymer Semiconductors

“…However, the D1 : 9 a based all‐PSCs showed a higher PCE of 6.39 % with a V oc of 0.73 V, a J sc of 13.47 mA cm −2 , and a FF of 65 % compared with the D1 : 9 b cells with a PCE of 5.35 %. The reduced 9 b performance is likely attributed to the relatively low μ e,SCLC and μ h,SCLC values of the D1 : 9 b blend . This fused PDI unit was further incorporated into the polymer backbone with an electron‐deficient 4,7‐dithienyl‐2,1,3‐benzothiadiazole (DTBT) moiety to afford a novel A‐A type polymer acceptor 10 , which showed greatly improved performance compared with its PDI‐based polymer analog 11 , reflecting the advantage of using two PDI moieties in the polymer backbone.…”

“…The reduced 9b performance is likely attributed to the relatively low m e,SCLC and m h,SCLC values of the D1:9b blend. [19] This fused PDI unit was further incorporated into the polymer backbone with an electron-deficient 4,7dithienyl-2,1,3-benzothiadiazole (DTBT) moiety to afford a novel A-A type polymera cceptor 10,which showedgreatlyimprovedp erformance compared with its PDI-based polymer analog 11,r eflecting the advantage of using two PDI moieties in the polymer backbone. The highest PCE of 6.23 %w as obtained from D1:10 based all-PSCs, which is the best performance for all-PSCsu sing af used PDI-based A-A type polymer acceptor reported so far.…”