Thieno[3,2-b]indole / 2,2′-bithiophene-based D-π-A dyes for dye sensitized solar cells.

In this work, new D-π-A dyes bearing thieno[3,2- b ]indole, 7-(tert -butyl)thieno[3,2- b ]indole or benzo[ g ]thieno[3,2- b ]indole as an electron-donating part, 2,2′-bithiophene unit as π-linker and 2-cyanoacrylic acid as an electron acceptor-anchoring part have been readily synthesized and used for dye-sensitized solar cells (DSSCs). In addition, thermal stability, optical and electrochemical properties of these dyes were investigated. The DSSCs based on dyes IS-BTh exhibited values of PCE in the range of 3.43–4.41 % under AM 1.5 G irradiation. The highest PCE value of 4.41 % (J sc = 11.61 mA cm−2, V oc = 0.64 V, FF = 0.59) was achieved for DSSC based on dye IS-BTh-1 , bearing thieno[3,2- b ]indole as an electron-donating part. The temperature dependencies of the photovoltaic parameters for DSSC based on dye IS-BTh-1 were investigated. Three new D-π-A compounds were synthesized and used as photosensitizers for dye-sensitized solar cells (DSSCs), and the highest power conversion efficiency of 4.41 % was achieved for DSSC based on dye IS-BTh-1. [Display omitted] • Novel D-π-A thieno[3,2- b ]indole based photosensitizers were synthesized and used for dye-sensitized solar cells (DSSCs). • The effect at modifying thieno[3,2- b ]indole donor part in the structure of these dyes was investigated. • The highest PCE value of 4.41 % was achieved for DSSC based on dye IS-BTh-1 , bearing thieno[3,2- b ]indole as an electron-donating part. • The temperature dependencies of the photovoltaic parameters for DSSC based on dye IS-BTh-1 were investigated. [ABSTRACT FROM AUTHOR]