Effects of electron-withdrawing group and electron-donating core combinations on physical properties and photovoltaic performance in D-π-A star-shaped small molecules

Luponosov YN, Min J, Solodukhin AN, Kozlov OV, Obrezkova MA, Peregudova SM, Ameri T, Chvalun SN, Pshenichnikov MS, Brabec C, Ponomarenko SA (2016)


Publication Type: Journal article

Publication year: 2016

Journal

Book Volume: 32

Pages Range: 157-168

DOI: 10.1016/j.orgel.2016.02.027

Abstract

The first representatives of star-shaped molecules having 3-alkylrhodanine (alkyl-Rh) electron-withdrawing groups, linked through bithiophene π-spacer with electron-donating either triphenylamine (TPA) or tris(2-methoxyphenyl)amine (m-TPA) core were synthesized. The physical properties and photovoltaic performance of these novel molecules with 3-ethylrhodanine groups were comprehensively studied and compared to their full analogs having dicyanovinyl (DCV) units as the other type of well-known and frequently used acceptor groups. On one hand, the former demonstrate several advantages such as higher solubility and better photovoltaic performance in bulk-heterojunction (BHJ) organics solar cells (OSCs) as compared to the latter. Nevertheless, the former have slightly lower optical/electrochemical bandgaps and higher thermooxidation stability. On the other hand, molecules of both series based on m-TPA core along with higher solubility and higher position of HOMO energy levels have more pronounced tendency to crystalize as compared to the TPA-based molecules. Detailed investigation of the structure-property relationships for these series of molecules revealed that donor and acceptor unit combinations influence both charge generation and charge transport/recombination properties, as demonstrated by the ultrafast photoinduced absorption spectroscopy, space charge limited current measurements and transient photovoltage technique. These results give more insight how to fine-tune and predict physical properties and photovoltaic performance of small molecules having either alkyl-Rh or DCV units in their chemical structures and thus providing a molecular design guideline for the next generation of high-performance photovoltaic materials.

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How to cite

APA:

Luponosov, Y.N., Min, J., Solodukhin, A.N., Kozlov, O.V., Obrezkova, M.A., Peregudova, S.M.,... Ponomarenko, S.A. (2016). Effects of electron-withdrawing group and electron-donating core combinations on physical properties and photovoltaic performance in D-π-A star-shaped small molecules. Organic Electronics, 32, 157-168. https://dx.doi.org/10.1016/j.orgel.2016.02.027

MLA:

Luponosov, Yuriy N., et al. "Effects of electron-withdrawing group and electron-donating core combinations on physical properties and photovoltaic performance in D-π-A star-shaped small molecules." Organic Electronics 32 (2016): 157-168.

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