New Alternating Copolymers of 3,6-Carbazoles and Dithienylbenzothiadiazoles: Synthesis, Characterization, and Application in Photovoltaics

✍ Scribed by Nicolas Berton; Chiara Ottone; Vanessa Labet; Rémi de Bettignies; Séverine Bailly; André Grand; Christophe Morell; Saïd Sadki; Frédéric Chandezon

• Book ID: 102940644
• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 775 KB
• Volume: 212
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.201100209

✦ Synopsis

Abstract

Three new low‐bandgap copolymers containing 3,6‐linked carbazole units are synthesized and characterized using a combination of spectroscopic and electrochemical techniques and DFT calculations. The electron‐withdrawing effect of the BTD units leads to a significant decrease of the optical bandgap from 2.59 eV for PBTC to 1.81 eV for PCDTBT, whereas pendant octyl chains on the thiophene ring lead to an increase of the gap to 2.05 eV for PCDOTBT due to steric hindrance. PBTC:PCBM photovoltaic devices exhibit a PCE of 0.35% with an EQE reaching 35% in the blue region of the solar spectrum whereas PCDTBT:PCBM blends are efficient over a wider spectral range due to the lower bandgap of PCDTBT.magnified image