Abstract
Unsymmetrical squaraine near-infrared (NIR) sensitizers with variable π-bridge units, based on the donor-π-squaraine core-acceptor structural motif, were synthesized and used as sensitizers for dye-sensitized solar cells. The phenothiazine as a donor group was linked to a squaraine core unit using various thiophene derivatives. Among them, three squaraine-based sensitizers have a carboxylic acid group as an electron-accepting group directly attached to the squaraine component, while one of four squaraine-based sensitizers has a cyanoacrylic acid as a more strongly electron-accepting group directly attached to the squaraine component. The sensitizers exhibited intense absorption in the NIR region and strong luminescence. The LUMO levels of the present squaraine-based sensitizers were slightly more negative than the conduction band edge of TiO2 photoanode. As a result, a solar cell based on the squaraine-based sensitizer containing a thiophene unit as a π-bridge unit and a carboxylic acid group as an electron-accepting group exhibited better photovoltaic performance with a JSC of 6.0 mA cm−2, a VOC of 448 mV, and an FF of 0.73, corresponding to an overall conversion efficiency η of 2.0%.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
