Synthesis and photovoltaic effect in red/near-infrared absorbing A-D-A-D-A-type oligothiophenes containing benzothiadiazole and thienothiadiazole central units

Luponosov YN, Min J, Khanin DA, Baran D, Pisarev SA, Peregudova SM, Dmitryakov PV, Chvalun SN, Cherkaev GV, Svidchenko EA, Ameri T, Brabec C, Ponomarenko SA (2015)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2015

Journal

Publisher: SPIE

Book Volume: 5

Journal Issue: 1

DOI: 10.1117/1.JPE.5.057213

Abstract

Two π-conjugated acceptor-donor-acceptor-donor-acceptor-type (A-D-A-D-A) oligothiophenes, TT-(2T-DCV-Hex) and BT-(2T-DCV-Hex) were designed and synthesized with thienothiadiazole (TT) or benzothiadiazole (BT) as the core and dicyanovinyl (DCV) as the terminal acceptor groups for comprehensively investigating and understanding structure-property relationships. The resulting oligomers were first characterized by thermal analysis, UV-Vis spectroscopy, and cyclic voltammetry. By simply changing the BT to TT core in these two oligothiophenes, the highest occupied molecular orbital levels were varied from-5.55 eV for BT-(2T-DCV-Hex) to-5.11 eV for TT-(2T-DCV-Hex), and the optical band gaps were varied from 1.72 eV for BT-(2T-DCV-Hex) to 1.25 eV for TT-(2T-DCV-Hex), ascribed to the stronger electron accepting character of the TT core. However, the power conversion efficiency of bulk heterojunction organic solar cells (OSCs) with TT-(2T-DCV-Hex) as donor and [6,6]-phenyl C70-butyric acid methyl ester (PC71BM) as acceptor was measured to be 0.04% only, which is much lower than that of BT-(2T-DCV-Hex):PC71BM (1.54%). Compared to the TT-(2T-DCV-Hex) system, the BT-(2T-DCV-Hex) based device shows smoother film surface morphology, and superior charge generation and charge carrier mobilities. Therefore, the results clearly demonstrate that in addition to modifying the alkyl side chains and p-bridge lengths, the design of new small molecules for high-performance OSCs should also aim to choose suitable acceptor units.

Authors with CRIS profile

Involved external institutions

Russian Academy of Sciences / Росси́йская акаде́мия нау́к (RAS) Russian Federation (RU) National Research Centre "Kurchatov Institute" / Hациональный исследовательский центр "Курчатовский Институт" Russian Federation (RU)

How to cite

APA:

Luponosov, Y.N., Min, J., Khanin, D.A., Baran, D., Pisarev, S.A., Peregudova, S.M.,... Ponomarenko, S.A. (2015). Synthesis and photovoltaic effect in red/near-infrared absorbing A-D-A-D-A-type oligothiophenes containing benzothiadiazole and thienothiadiazole central units. Journal of Photonics for Energy, 5(1). https://dx.doi.org/10.1117/1.JPE.5.057213

MLA:

Luponosov, Yuriy N., et al. "Synthesis and photovoltaic effect in red/near-infrared absorbing A-D-A-D-A-type oligothiophenes containing benzothiadiazole and thienothiadiazole central units." Journal of Photonics for Energy 5.1 (2015).

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