Design of OsII‐based Sensitizers for Dye‐Sensitized Solar Cells: Influence of Heterocyclic Ancillaries. Issue 8 (10th July 2013)

• Record Type: Journal Article
• Authors: Hu, Fa‐Chun; Wang, Sheng‐Wei; Planells, Miquel; Robertson, Neil; Padhy, Harihara; Du, Bo‐Sian; Chi, Yun; Yang, Po‐Fan; Lin, Hao‐Wu; Lee, Gene‐Hsiang; Chou, Pi‐Tai
• Is Part Of: ChemSusChem. Volume 6:Issue 8(2013:Aug.)
• Page Start: 1366
• Page End: 1375
• Publication Date: 2013-07-10
• Subjects: Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201300417
• Languages: English
• ISSNs: 1864-5631

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A series of Os<sup>II</sup> sensitizers (<bold>TFOS‐<italic>x</italic></bold>, in which <italic><bold>x</bold></italic>=1, 2, or 3) with a single 4, 4′‐dicarboxy‐2, 2′‐dipyridine (H<sub>2</sub>dcbpy) anchor and two chelating 2‐pyridyl (or 2‐pyrimidyl) triazolate ancillaries was successfully prepared. Single‐crystal X‐ray structural analysis showed that the core geometry of the Os<sup>II</sup>‐based sensitizers consisted of one H<sub>2</sub>dcbpy unit and two eclipsed <italic>cis</italic>‐triazolate fragments; this was notably different from the Ru<sup>II</sup>‐based counterparts, in which the azolate (both pyrazolate and triazolate) fragments are located at the mutual <italic>trans</italic>‐positions. The basic properties were extensively probed by using spectroscopic and electrochemical methods as well as time‐dependent density functional theory (TD‐DFT) calculations. Fabrication of dye‐sensitized solar cells (DSCs) was then attempted by using the I<sup>−</sup>/I<sub>3</sub><sup>−</sup>‐based electrolyte solution. One such DSC device, which utilized <bold>TFOS‐2</bold> as the sensitizer, showed promising performance characteristics with a short‐circuit current density (<italic>J</italic><sub>SC</sub>) of 15.7 mA cm<sup>−2</sup>, an open‐circuit voltage of 610 mV, a fill factor of 0.63, and a power conversion efficiency of 6.08 % under AM 1.5G simulated one‐sun irradiation. Importantly, adequate incident photon‐to‐current conversion efficiency performances were observed for all <bold>TFOS</bold> derivatives over the wide spectral region of 450 to 950 nm, showing a panchromatic light harvesting capability that extended into the near‐infrared regime. Our results underlined a feasible strategy for maximizing <italic>J</italic><sub>SC</sub> and increasing the efficiency of DSCs.</p> </abstract>