Series of D-π-A system based on isoindigo dyes for DSSC: Synthesis, electrochemical and photovoltaic properties

Novel D-π-A system organic dyes (ID1, ID2 and ID3) based on isoindigo (ID), which contain triphenylamine (ID1) or isoindigo (ID2 and ID3) as electron donors, isoindigo and thiophene as a π-conjugated system and a cyanoacrylic acid moiety as an electron acceptor and anchoring group, have been then synthesized and characterized by 1H NMR, UV–vis, CV. Dye-sensitized solar cells (DSSCs) based on these dyes were also fabricated and tested. As the photovoltaic performance tests demonstrated, the ID1 exhibits broader absorption spectra, higher maximum incident photon-to-current conversion efficiency (IPCE) and maximum photon-to-electron conversion efficiency (η) of 3.33% under 100 mW/cm2 simulated AM 1.5G solar irradiation.