A maskless synthesis of TiO2-nanofiber-based hierarchical structures for solid-state dye-sensitized solar cells with improved performance

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• 作者：Dharani Sabba (8) (9)
  Shweta Agarwala (9)
  Stevin S Pramana (8)
  Subodh Mhaisalkar (8) (9)
  
• 关键词：Electrospinning ; Nanofibers ; Hydrothermal ; Hierarchical ; Solid ; state dye ; sensitized solar cells ; Dye loading ; Charge recombination
• 刊名：Nanoscale Research Letters
• 出版年：2014
• 出版时间：December 2014
• 年：2014
• 卷：9
• 期：1
• 全文大小：1,388 KB
• 作者单位：Dharani Sabba (8) (9)
  Shweta Agarwala (9)
  Stevin S Pramana (8)
  Subodh Mhaisalkar (8) (9)
  
  8. School of Materials Science and Engineering, Nanyang Technological University, 639798, Kragujevac, Singapore
  9. Energy Research Institute at NTU (ERI@N), Research Techno Plaza, Nanyang Technological University, 50 Nanyang Drive, 637553, Kragujevac, Singapore
  
• ISSN：1556-276X

文摘

TiO2ub> hierarchical nanostructures with secondary growth have been successfully synthesized on electrospun nanofibers via surfactant-free hydrothermal route. The effect of hydrothermal reaction time on the secondary nanostructures has been studied. The synthesized nanostructures comprise electrospun nanofibers which are polycrystalline with anatase phase and have single crystalline, rutile TiO2ub> nanorod-like structures growing on them. These secondary nanostructures have a preferential growth direction [110]. UV–vis spectroscopy measurements point to better dye loading capability and incident photon to current conversion efficiency spectra show enhanced light harvesting of the synthesized hierarchical structures. Concomitantly, the dye molecules act as spacers between the conduction band electrons of TiO2ub> and holes in the hole transporting medium, i.e., spiro-OMeTAD and thus enhance open circuit voltage. The charge transport and recombination effects are characterized by electrochemical impedance spectroscopy measurements. As a result of improved light harvesting, dye loading, and reduced recombination losses, the hierarchical nanofibers yield 2.14% electrochemical conversion efficiency which is 50% higher than the efficiency obtained by plain nanofibers.