Photovoltaic Performance of Dye-Sensitized Solar Cells with a Solid-State Redox Mediator Based on an Ionic Liquid and Hole-Transporting Triphenylamine Compound

• Main Authors: Choi, B. (Author), Han, Y.S (Author), Kong, M. (Author), Oh, D.H (Author)
• Format: Article
• Language: English
• Published: MDPI 2022
• Subjects: 1-methyl-3-propylimidazolium iodide; 4-tert butylpyridine; 4-tert-Butylpyridine; Dye- sensitized solar cells; dye-sensitized solar cell; Dye-sensitized solar cells; Hole mobility; Hole transporting; ionic liquid; Ionic liquids; m-MTDATA; M-MTDATA; Photovoltaic performance; Power conversion efficiencies; Redox mediators; Solar power generation; solid-state redox mediator; Solid-state redox mediator; Triphenylamines
• Online Access: View Fulltext in Publisher
• ISBN: 19961073 (ISSN)
• DOI: 10.3390/en15082765

An ionic liquid, 1-methyl-3-propylimidazolium iodide (MPII), was solidified with an organic hole-transporting material, 4,4′,4′′-tris[(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), and the resulting solid-state redox mediator (RM) (m-MTDATA-solidified MPII) was employed in solar devices to realize solid-state dye-sensitized solar cells (sDSSCs). Solar devices with only MPII or m-MTDATA as an RM showed almost 0 mA/cm2 of short-circuit current (Jsc) and thus 0% power conversion efficiency (PCE). However, an sDSSC with the m-MTDATA-solidified MPII exhibited 4.61 mA/cm2 of Jsc and 1.80% PCE. It was found that the increased Jsc and PCE were due to the formation of I3−, which resulted from a reaction between the iodie (I−) of MPII and m-MTDATA cation. Further enhancement in both Jsc (9.43 mA/cm2) and PCE (4.20%) was observed in an sDSSC with 4-tert butylpyridine (TBP) as well as with m-MTDATA-solidified MPII. We attributed the significant increase (about 230%) in PCE to the lowered diffusion resistance of I−/I3− ions in the solid-state RM composed of the m-MTDATA-solidified MPII and TBP, arising from TBP’s role as a plasticizer. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.