One-Step Synthesis of Precursor Oligomers for Organic Photovoltaics: A Comparative Study between Polymers and Small Molecules
Artikel i vetenskaplig tidskrift, 2015

Two series of oligomers TQ and rhodanine end-capped TQ-DR were synthesized using a facile one-step method. Their optical, electrical, and thermal properties and photovoltaic performances were systematically investigated and compared. The TQ series of oligomers were found to be amorphous, whereas the TQ-DR series are semicrystalline. For the TQ oligomers, the results obtained in solar cells show that as the chain length of the oligomers increases, an increase in power conversion efficiency (PCE) is obtained. However, when introducing 3-ethylrhodanine into the TQ oligomers as end groups, the PCE of the TQ-DR series of oligomers decreases as the chain length increases. Moreover, the TQ-DR series of oligomers give much higher performances compared to the original amorphous TQ series of oligomers owing to the improved extinction coefficient (epsilon) and crystallinity afforded by the rhodanine. In particular, the highly crystalline oligomer TQ5-DR, which has the shortest conjugation length shows a high hole mobility of 0.034 cm(2) V-1 s(-1) and a high PCE of 3.14%, which is the highest efficiency out of all of the six oligomers. The structure-property correlations for all of the oligomers and the TQ1 polymer demonstrate that structural control of enhanced intermolecular interactions and crystallinity is a key for small molecules/oligomers to achieve high mobilities, which is an essential requirement for use in OPVs.

oligomers

one-step method

organic photovoltaics

hole mobility

amorphous

crystallinity

Författare

W. Li

South China University of Technology

Chalmers University of Technology

D. J. Wang

Linköpings universitet

S. H. Wang

Linköpings universitet

W. Ma

Xi'an Jiaotong University

Svante Hedström

Lunds universitet

David James

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

Xiaofeng Xu

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

P. Persson

Lunds universitet

S. Fabiano

Linköpings universitet

M. Berggren

Linköpings universitet

Olle Inganäs

Linköpings universitet

F. Huang

South China University of Technology

Ergang Wang

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Polymerteknologi

ACS Applied Materials & Interfaces

1944-8244 (ISSN) 1944-8252 (eISSN)

Vol. 7 27106-27114

Ämneskategorier

Materialteknik

DOI

10.1021/acsami.5b09460