Synergistically improved photovoltaic performances of dye-sensitized solar cells with metal-free organic cosensitizer and hybrid rGO-TiO2 photoanode

• Published in: Dyes and pigments Vol. 209; p. 110892
• Main Authors: Subalakshmi, Kumar, Chung, Woochan, Lee, Sejoon
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2023
• Subjects: Cosensitizer; Dye-sensitized solar cell; Enhanced power conversion efficiency; Metal-free organic dye; rGO-TiO2 nanocomposite; Cosensitizer; Dye-sensitized solar cell; Metal-free organic dye; rGO-TiO2 nanocomposite; Enhanced power conversion efficiency
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2022.110892

The photovoltaic performances of the dye-sensitized solar cells were considerably improved via comprising the device structure with the metal-free organic dye cosensitizer and the hybrid photoanode. The cosensitizer was composed of Eosin Y and Coumarin (EY-CM) dyes, and the hybrid photoanode was constructed with the reduced graphene oxide-anchored titanium dioxide (rGO-TiO2) nanocomposites. Due to the aggregation of highly conductive rGO with semiconductive TiO2, the nanocomposites exhibited the decreased interfacial resistance; hence, the electron transport could be improved in the solid-state medium of the photoanode. Meanwhile, the cosensitization of EY-CM dyes could give rise to the increased photon absorbance at the wide spectral range; and their energy level alignment with rGO-TiO2 could lead to the enhanced hopping conduction of the photo-generated electrons. Furthermore, the configuration of rGO-TiO2/EY-CM allowed us to increase the electron injection lifetime, which could reduce the photocarrier recombination at the photoanode/sensitizer interface. Owing to the synergetic effects from both the rGO-TiO2 hybrid photoanode and the EY-CM cosensitizer, the fabricated dye-sensitized solar cell eventually showed the increased power conversion efficiency up to ∼6.14% under 1-Sun illumination with 100 mW/cm2. [Display omitted] •The DSSCs were fabricated in the form of the hybrid photoanode/cosensitizer scheme.•The hybrid photoanode material of rGO-TiO2 was prepared by the hydrothermal method.•The cosensitizer was configured with double dyes of Eosin Y and Coumarin (EY-CM).•The rGO-TiO2/EY-CM scheme improved both electron lifetime and chemical capacitance.•The proposed scheme synergistically enhanced the photovoltaic performances.