n-Type core effect on perylene diimide based acceptors for panchromatic fullerene-free organic solar cells

作者：Eom Seung Hun; Kim Hee Su; Do Hee Jin; Lee Un Hak; Wibowo Febrian Tri Adhi; Hwang Do Hoon; Yoon Sung Cheol; Jung In Hwan

来源：Dyes and Pigments, 2018, 156: 318-325.

DOI：10.1016/j.dyepig.2018.04.018

• Non-fullerene acceptor
• Fullerene-free organic solar cells
• n-Type core effect
• Perylene diimide
• Panchromatic absorption

Perylene diimide (PDI) based high bandgap acceptors, DTBTP, DTF2BTP, and DTF2TZP, are synthesized for use in fullerene-free organic solar cells. The two PDI rings are connected to the end of the n-type core, forming a PDI-n-type core-PDI structure. Several n-type core materials, 4,7-dithieno-2,1,3-benzothiadiazole (DTBT), 5,6-difluoro-4,7-dithieno-2,1,3-benzothiadiazole (DTF2BT), and 4,6-difluoro-2H-benzo[d][1,2,3]triazole (DTF2TZ), are incorporated in the PDI acceptors and the n-type core effect on photovoltaic properties is studies. The introduction of alkyl side chains onto the core structure weakened the intermolecular interaction, whereas fluorination of the core structure improved the backbone planarity and intermolecular ordering. DTF2BTP having a planar core structure without bulky alkyl chains yielded the best power conversion efficiency, 4.41%, when mixed with PTB7-Th donor. The n-type core structure was beneficial in terms of increasing the electron accepting properties and the absorption in the high bandgap region of non-fullerene acceptors.

• 出版日期2018-9