Title
Design and Synthesis of Novel NIR Sensitive Unsymmetrical Squaraine Dyes for Molecular Photovoltaics
Author
Pradhan, Safalmani, Yuki Kurokawa, and Shyam Sudhir Pandey
Year
2023
Journal
Physica Status Solidi (a)
Abstract
Two novel NIR-sensitive unsymmetrical squaraine dyes, SQ-258 and SQ-259, for their suitability as a sensitizer in dye-sensitized solar cells (DSSCs) were designed and synthesized, followed by photophysical and photovoltaic characterizations. It was demonstrated that introducing a 1,3-indandione acceptor unit in the central squaric acid core of SQ-259 led to the suppression of dye aggregation owing to its non-planar molecular geometry and the broadening of the optical absorption and photon harvesting window up to 800 nm. Owing to the extended wavelength photon harvesting, SQ-259 improved the photoconversion efficiency (PCE) compared to its SQ-258 dye counterpart. However, despite its wide wavelength photon harvesting, the improvement in the PCE of SQ-259 was less pronounced, and this has been attributed to the small driving force for injection of electrons (0.29 eV), hampered electronic coupling, and decreased lifetime for resistance to recombination (7.9 ms), which was confirmed by the cyclic voltammetry, quantum chemical calculation, and electrochemical impedance spectroscopic investigations, respectively. This article is protected by copyright. All rights reserved.
Instrument
V-550,FP-6600
Keywords
Sensitizer in dye-sensitized solar cells (DSSCs)