Ladder‐Type Nonacyclic Arene Bis(thieno[3,2‐b]thieno)cyclopentafluorene as a Promising Building Block for Non‐Fullerene Acceptors

Abstract

The ladder-type nonacyclic arene (bis(thieno[3,2b]thieno)cyclopentafluorene (BTTF)) has been designed and synthesized through fusing thienothiophenes with the fluorene core from the synthon of dimethyl9 ,9-dioctyl-2,7-bis(thieno[3,2-b]thiophen-2-yl)fluorene-3,6-dicarboxylate. With BTTF as the central donor unit, an ovel acceptor-donor-acceptor (A-D-A) type non-fullerene small-molecule acceptor (BTTFIC)w as prepared with 1,1-dicyanomethylene-3-indanones (IC) as the peripheral acceptor units.T he energy level of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of BTTFIC locate at À5.56 and À3.95 eV,r espectively,p resentingalow opticalb and gap of 1.58 eV.E ncouragingly,p olymer solar cells based on the blends of BTTFIC with both the representative wide-andl ow-bandgap polymer donors (PBDB-T, 1.82 eV.P TB7-Th, 1.58 eV) offer powerc onversion efficiencies over 8% (8.78 AE 0.18 %f or PBDB-T:BTTFIC and 8.18 AE 0.29 % for PTB7-Th:BTTFIC). These results highlightt he advantage of ladder-type BTTF on the preparation of nonfullerene acceptors with extended conjugated backbones.[a] X.Scheme2.Synthesis of ladder-typenonacyclic arene of bis(thieno[3,2-b]thieno)cyclopentafluorene (BTTF)and non-fullerene acceptorofBTTFIC.

Star‐Shaped Non‐Fullerene Small Acceptors for Organic Solar Cells

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Flexible Organic Solar Cells: Progress and Challenges

“…In the past 5 years, PCEs of 12–16% have been achieved in various NFAs cases via rational designing of the A and D unit chemical structures. [ 1,39–48 ] Very recently, the efficiency has been pushed to ≈18% owing to the development of novel NFAs (Y6 and derivatives) and efficient polymer donors. [ 49 ] Consequently, with the continuous development of efficient photoactive materials, significant progress has been achieved for flexible OSCs in recent years.…”

Recent progress on all‐small molecule organic solar cells using small‐molecule nonfullerene acceptors

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