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Efficient Performance of Electrostatic Spray-Deposited TiO 2 Blocking Layers in Dye-Sensitized Solar Cells after Swift Heavy Ion Beam Irradiation

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ABSTRACT

A compact TiO2 layer (~1.1 μm) prepared by electrostatic spray deposition (ESD) and swift heavy ion beam (SHI) irradiation using oxygen ions onto a fluorinated tin oxide (FTO) conducting substrate showed enhancement of photovoltaic performance in dye-sensitized solar cells (DSSCs). The short circuit current density (Jsc = 12.2 mA cm-2) of DSSCs was found to increase significantly when an ESD technique was applied for fabrication of the TiO2 blocking layer, compared to a conventional spin-coated layer (Jsc = 8.9 mA cm-2). When SHI irradiation of oxygen ions of fluence 1 × 1013 ions/cm2 was carried out on the ESD TiO2, it was found that the energy conversion efficiency improved mainly due to the increase in open circuit voltage of DSSCs. This increased energy conversion efficiency seems to be associated with improved electronic energy transfer by increasing the densification of the blocking layer and improving the adhesion between the blocking layer and the FTO substrate. The adhesion results from instantaneous local melting of the TiO2 particles. An increase in the electron transport from the blocking layer may also retard the electron recombination process due to the oxidized species present in the electrolyte. These findings from novel treatments using ESD and SHI irradiation techniques may provide a new tool to improve the photovoltaic performance of DSSCs.

No MeSH data available.


IPCE spectra of DSSCs using different TiO2blocking layers.
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Figure 5: IPCE spectra of DSSCs using different TiO2blocking layers.

Mentions: As shown in Figure 5, the ESD TiO2 blocking layer DSSC (pristine cell) shows higher IPCE (maximum up to about ~53% at 530–540 nm) than the reference cell over the whole range of light wavelengths. This clearly demonstrates a ~16% improvement in external quantum efficiency from reducing the electron losses at FTO/TiO2 interfaces. It appears that the ESD is more efficient than the spin coating in terms of improving IPCE due to the formation of continuous films. Further, substantial improvement in IPCE was identified at lower wavelengths (380–420 nm), attributable to the SHI irradiation on the TiO2 blocking layer. The IPCE can be rationalized using the following relation [30],


Efficient Performance of Electrostatic Spray-Deposited TiO 2 Blocking Layers in Dye-Sensitized Solar Cells after Swift Heavy Ion Beam Irradiation
IPCE spectra of DSSCs using different TiO2blocking layers.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211366&req=5

Figure 5: IPCE spectra of DSSCs using different TiO2blocking layers.
Mentions: As shown in Figure 5, the ESD TiO2 blocking layer DSSC (pristine cell) shows higher IPCE (maximum up to about ~53% at 530–540 nm) than the reference cell over the whole range of light wavelengths. This clearly demonstrates a ~16% improvement in external quantum efficiency from reducing the electron losses at FTO/TiO2 interfaces. It appears that the ESD is more efficient than the spin coating in terms of improving IPCE due to the formation of continuous films. Further, substantial improvement in IPCE was identified at lower wavelengths (380–420 nm), attributable to the SHI irradiation on the TiO2 blocking layer. The IPCE can be rationalized using the following relation [30],

View Article: PubMed Central - HTML - PubMed

ABSTRACT

A compact TiO2 layer (~1.1 μm) prepared by electrostatic spray deposition (ESD) and swift heavy ion beam (SHI) irradiation using oxygen ions onto a fluorinated tin oxide (FTO) conducting substrate showed enhancement of photovoltaic performance in dye-sensitized solar cells (DSSCs). The short circuit current density (Jsc = 12.2 mA cm-2) of DSSCs was found to increase significantly when an ESD technique was applied for fabrication of the TiO2 blocking layer, compared to a conventional spin-coated layer (Jsc = 8.9 mA cm-2). When SHI irradiation of oxygen ions of fluence 1 × 1013 ions/cm2 was carried out on the ESD TiO2, it was found that the energy conversion efficiency improved mainly due to the increase in open circuit voltage of DSSCs. This increased energy conversion efficiency seems to be associated with improved electronic energy transfer by increasing the densification of the blocking layer and improving the adhesion between the blocking layer and the FTO substrate. The adhesion results from instantaneous local melting of the TiO2 particles. An increase in the electron transport from the blocking layer may also retard the electron recombination process due to the oxidized species present in the electrolyte. These findings from novel treatments using ESD and SHI irradiation techniques may provide a new tool to improve the photovoltaic performance of DSSCs.

No MeSH data available.