Effects of oligothiophene π-bridge length on physical and photovoltaic properties of star-shaped molecules for bulk heterojunction solar cells

Min J, Luponosov YN, Baran D, Chvalun SN, Shcherbina MA, Bakirov AV, Dmitryakov PV, Peregudova SM, Kausch-Busies N, Ponomarenko SA, Ameri T, Brabec C (2014)

Publication Type: Journal article

Publication year: 2014

Journal

Book Volume: 2

Pages Range: 16135-16147

Journal Issue: 38

DOI: 10.1039/C4TA01933D

Abstract

The preparation of four different star-shaped donor (D)-π-acceptor (A) small molecules (N(Ph-1T-DCN-Me)3, N(Ph-2T-DCN-Me)3, N(Ph-2T-DCN-Hex)3 and N(Ph-3T-DCN-Hex)3) possessing various oligothiophene π-bridge lengths and their use in solution-processed bulk heterojunction small molecule solar cells is reported. Optical and electrochemical data show that increasing oligothiophene π-bridge length leads to a decrease of the optical band gap due to a parallel increase of the highest occupied molecular orbital (HOMO) level. Furthermore, subtle modifications of a molecular π-bridge length strongly affect the thermal behavior, solubility, crystallization, film morphology and charge carrier mobility, which in turn significantly change the device performance. Although the moderately increasing oligothiophene π-bridge length uplifts the HOMO level, it nevertheless induces an increase of the efficiency of the resulting solar cells due to a simultaneous improvement of the short circuit current (Jsc) and fill factor (FF). The study demonstrates that such an approach can represent an interesting tool for the effective modulation of the photovoltaic properties of the organic solar cells (OSCs) at a moderate cost.

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Additional Organisation(s)

Involved external institutions

National Research Centre "Kurchatov Institute" / Hациональный исследовательский центр "Курчатовский Институт" Russian Federation (RU) Russian Academy of Sciences / Росси́йская акаде́мия нау́к (RAS) Russian Federation (RU) Heraeus Precious Metals GmbH & Co. KG Germany (DE)

How to cite

APA:

Min, J., Luponosov, Y.N., Baran, D., Chvalun, S.N., Shcherbina, M.A., Bakirov, A.V.,... Brabec, C. (2014). Effects of oligothiophene π-bridge length on physical and photovoltaic properties of star-shaped molecules for bulk heterojunction solar cells. Journal of Materials Chemistry A, 2(38), 16135-16147. https://dx.doi.org/10.1039/C4TA01933D

MLA:

Min, Jie, et al. "Effects of oligothiophene π-bridge length on physical and photovoltaic properties of star-shaped molecules for bulk heterojunction solar cells." Journal of Materials Chemistry A 2.38 (2014): 16135-16147.

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