Synthesis and photovoltaic properties of a new donor-acceptor conjugated polymer based on fluorinated benzothiadiazole units

H. Medlej , A. Nourdine (1) , Hussein Awada (2) , Mamatimin Abbas (3) , Christine Lartigau-Dagron (2) , G. Wantz (3) , L. Flandin (1)

1 LMOPS - Matériaux organiques à propriétés spécifiques
2 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux
3 IMS - Laboratoire de l'intégration, du matériau au système

A novel fluorinated copolymer (PDTSffBT) based on dithienosilole donor unit and fluorinated benzothiadiazole acceptor unit has been synthesized for polymer solar cells. This copolymer exhibits a deeper HOMO energy level compared to that of hydrogenated benzothiadiazole-based copolymer (PDTSBT), resulting in high open-circuit voltages well exceeding 0.75 V. The introduction of the two electron-withdrawing fluorine atoms on the benzothiadiazole unit also leads to an increase in the molar extinction coefficient as well as the interchain interaction in the PDTSffBT copolymer with respect to its analogue PDTSBT copolymer. Power conversion efficiency (PCE) of the device using PDTSffBT:PC71BM as active layer (2.93 %) is much higher than of a PDTSBT:PC71BM (1.64 %) counterpart under identical conditions.

Mots clés: Photovoltaic cells; Performance evaluation; Energy states; Polymers; Photonic band gap; Photovoltaic systems

Domaines: Chimie; Polymères

H. Medlej, A. Nourdine, Hussein Awada, Mamatimin Abbas, Christine Lartigau-Dagron, et al.. Synthesis and photovoltaic properties of a new donor-acceptor conjugated polymer based on fluorinated benzothiadiazole units. 2014 IEEE 40th Photovoltaic Specialist Conference (PVSC), Jun 2014, Denver, United States. pp.1766-1769, ⟨10.1109/PVSC.2014.6925263⟩. ⟨hal-01559884⟩