Applied Nanoscience

, Volume 8, Issue 5, pp 1001–1013 | Cite as

Dual functional passivating layer of graphene/TiO2 for improved performance of dye-sensitized solar cells

  • Muhammad Umair Shahid
  • Norani Muti MohamedEmail author
  • Ali Samer Muhsan
  • Mehboob Khatani
  • Robabeh Bashiri
  • Siti Nur Azella Zaine
  • Adel Eskandar Shamsudin
Original Article


The FTO/TiO2 interface plays a crucial role in the performance of dye-sensitized solar cells (DSSCs). The uneven microstructure morphology of FTO (fluorine-doped tin oxide) glass surface and high porosity of TiO2 layer produce tiny gaps and voids at the FTO/TiO2 interface that breaks the connectivity, leading to an increase in the recombination process. In the current work, a dual functional passivating layer is introduced by the combination of the graphene/TiO2 compact layer. The excellent mobility and flexibility of graphene is capitalized using its layer to fill the voids in the FTO surface, which can consequently reduce the charge transfer resistance at the interface, while the added TiO2 compact layer avoids direct contact with the electrolyte thus reducing the recombination. Graphene was synthesized by the facile solvent exfoliation method with the assistance of the probe sonication process. The parameters of sonication were optimized to achieve high-quality concentrated graphene inks (0.177–0.51 mg/ml). Raman spectroscopy and transmission electron microscopy (TEM) revealed that the graphene obtained is of a few-layer type. Electrochemical impedance spectroscopy (EIS) analysis indicated that the incorporated compact layer of graphene/TiO2 was capable of accelerating the charge transfer and reducing the recombination process at the FTO/TiO2 interface. Consequently, the photoconversion efficiency (PCE) for the device (1 cm2 active area) with double-coated graphene layer under one sun irradiation (AM 1.5) was found to be 49.49% higher than the conventional one.


Few-layered graphene FTO glass Dye-sensitized solar cells Exfoliation Passivating layer Probe sonication TiO2 compact layer 



The authors would like to thank Universiti Teknologi PETRONAS, Malaysia and Centre of Innovative Nanostructures and Nanodevices (COINN) for financial and technical supports which made this research work feasible.

Supplementary material

13204_2018_685_MOESM1_ESM.docx (2.1 mb)
Supplementary material 1 (DOCX 2142 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Muhammad Umair Shahid
    • 1
    • 2
  • Norani Muti Mohamed
    • 1
    • 2
    Email author
  • Ali Samer Muhsan
    • 3
  • Mehboob Khatani
    • 4
  • Robabeh Bashiri
    • 1
  • Siti Nur Azella Zaine
    • 1
    • 2
  • Adel Eskandar Shamsudin
    • 4
  1. 1.Centre of Innovative Nanostructures and Nanodevices (COINN)Universiti Teknologi PETRONASBandar Seri IskandarMalaysia
  2. 2.Fundamental and Applied Sciences DepartmentUniversiti Teknologi PETRONASBandar Seri IskandarMalaysia
  3. 3.Petroleum Engineering DepartmentUniversiti Teknologi PETRONASBandar Seri IskandarMalaysia
  4. 4.Electrical and Electronic Engineering DepartmentUniversiti Teknologi PETRONASBandar Seri IskandarMalaysia

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