Carbazole-bridged double D-A dye for efficient dye-sensitized solar cell

Abstract

© 2014 Elsevier B.V. All rights reserved. A di-anchoring organic dye based on an acceptorπ spacerdonorsecondary donordonorπ spacer acceptor structural motif has been synthesized and used as a sensitizer for dye-sensitized solar cells (DSSCs). The new synthetic approach uses two π spacers, two acceptors and two different donors such as arylamino and carbazole units. The double donoracceptor dye CBZ-3 is linked by a carbazole unit as a secondary donor which increases the donoracceptor strength of the dye and proved to increase the η and Jscvalues of the photovoltaic cell compared to the corresponding mono-anchoring system CBZ-2 and the monodonor dye CBZ-1. With the non-planar structure of the arylamino group and the alkyl chains which efficiently prevent the formation of the dye aggregates, the dye exhibited a high open-circuit photovoltage (Voc) of 650 mV, a short-circuit photocurrent density (Jsc) of 7.20 mA cm-2and the solar energy-to-electricity conversion efficiency (η) of 3.23%.