EIS analysis on low temperature fabrication of TiO2 porous films for dye-sensitized solar cells

Hsu, Chao Po; Lee, Kun‐Mu; Huang, Joseph Tai Wei; Lin, Chia Yu; Lee, Chia-Hua; Wang, Lih Ping; Tsai, Song Yeu; Ho, Kuo–Chuan

doi:10.1016/j.electacta.2008.01.104

Cited by 235 publications

(96 citation statements)

References 22 publications

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“…The Nyquist plots are reported in Figure 7. In general, the increase of the semicircle radius means a growth of the internal resistances of the device [26]. For the C106, DNF01 hp, DNF11 and DNF12 hp dyes, it was found that the charge-transfer resistance values at the Nb 2 O 5 /dye/electrolyte interface are comparable with those of anatase-based devices.…”

Section: Electrochemical Impedance Spectroscopy (Eis)supporting

confidence: 50%

Test of Different Sensitizing Dyes in Dye-Sensitized Solar Cells Based on Nb2O5 Photoanodes

Latini

Panetta

2018

Energies

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High-performance dyes routinely employed in TiO 2 -based dye-sensitized solar cells (DSSCs) were tested in cells assembled using Nb 2 O 5 nanostructure-based photoanodes. The sensitizers were chosen among both metal-complex (two Ru-based, N749 and C106, and one Zn-based dye, DNF12) and metal-free organic dyes (DNF01, DNF11 and DNF15). Two different sensitization processes were performed: the one commonly used for TiO 2 photoanodes, and a new process relying on high pressure by autoclavation. The assembled cells were characterized by current density-voltage (J-V) curves under air mass (AM) 1.5 G illumination and in the dark, incident photon-to-current efficiency (IPCE) measurements, and electrochemical impedance spectroscopy. The tested cells show different proportional efficiencies of the dyes under investigation for Nb 2 O 5 -and TiO 2 -based devices. Furthermore, the results were compared with those obtained in our previous work using N719 anchored on Nb 2 O 5 . A remarkable efficiency value of 4.4% under 1 sun illumination was achieved by coupling the C106 dye with a nonvolatile electrolyte. This value is higher than the one attained under the same conditions by using N719.

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Section: Electrochemical Impedance Spectroscopy (Eis)supporting

confidence: 50%

Test of Different Sensitizing Dyes in Dye-Sensitized Solar Cells Based on Nb2O5 Photoanodes

Latini

Panetta

2018

Energies

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“…In all the EIS spectra, two well-defined semicircles were observed in the high-frequency region (>1 kHz) and in the frequency region of 100-1 Hz, respectively. According to recent analysis on the EIS spectra of the DSSCs, [29] the first semicircle in the high-frequency region represents the redox reaction of I À /I 3 À at the Pt/electrolyte interface, and the other semicircle denotes the electron transfer at the oxide/dye/electrolyte interface. Since there is no current passing through the external circuit at V oc condition, the electrons injected into the oxide semiconductor must be recombined by …”

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confidence: 99%

TiO₂‐Coated Multilayered SnO₂ Hollow Microspheres for Dye‐Sensitized Solar Cells

et al. 2009

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Dye-sensitized solar cells (DSSCs) have attracted extensive interest in past decade as a promising candidate for the future generation of cost-effective photovoltaic solar cells. [1][2][3][4][5] Since the first demonstration of 10.4% photoconversion efficiency on TiO 2 -based DSSC, [6] intensive work in DSSC research has been devoted to the synthetic chemistry and structural and photovoltaic characterization of mesoporous nanocrystalline TiO 2 materials. [7][8][9] In contrast, other metal oxide semiconductors, such as tin and zinc oxides, have received less attention, though they have required band-gap widths and photoelectrochemical properties as TiO 2 . In fact, SnO 2 has at least two advantageous features compared to TiO 2 for DSSC applications: its higher electron mobility ($100-200 cm 2 V À1 S À1[10]) than TiO 2 ($0.1-1.0 cm 2 V À1 S À1[11]), suggesting a faster diffusion transport of photoinduced electrons in SnO 2 than in TiO 2 ; and its larger band gap (3.6 eV) than anatase TiO 2 (3.2 eV), which would create fewer oxidative holes in the valence band, so as to facilitate the long-term stability of DSSCs. However, SnO 2 -based DSSCs were developed with less success, and the conversion efficiencies of SnO 2 photoelectrodes reported so far are much less than those of TiO 2 . [12,13]

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“…[ 31 ] The lower TiO 2 /electrolyte impedance values for untreated S1 cells compared to untreated P25 cells (evidenced by the size of the respective ω 2 semi-circles) can be attributed to the hierarchical and interpenetrating porous microstructure of the macro-and semicircles corresponding to the three main photoelectrochemical processes occurring during the cell operation: 1) Nernstian diffusion of iodine/iodide species through the electrolyte and TiO 2 fi lm; 2) electron transfer and recombination kinetics at the TiO 2 /electrolyte interface; and 3) electron transfer at the Pt/ electrolyte interface. [27][28][29][30] The semicircle associated with the Nernstian diffusion process is usually seen at frequencies below 0.1 Hz and requires a long acquisition time. It is not recorded in our experiments and only two semicircles associated with charge transfer kinetics at the Pt/electrolyte interface and electron transfer and recombination kinetics at the TiO 2 /electrolyte mesopores in the materials.…”

Section: Resultsmentioning

confidence: 99%

Improving Microstructured TiO₂ Photoanodes for Dye Sensitized Solar Cells by Simple Surface Treatment

Ahmed

Pasquier

Asefa

et al. 2011

Advanced Energy Materials

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TiCl4 surface treatment studies of porous electrode structure of TiO2 aggregates synthesized using an acidic precursor and CTAB as a templating agent are carried out in order to understand and improve upon recombination kinetics in the photonanode film matrix, together with enhancing the intrinsic light scattering. The key beneficial features of the photoanode included high surface roughness, necessary for superior dye adsorption, nanocrystallite aggregates leading to diffuse light scattering within the film matrix, and a hierarchical macro‐ and mesopore structure allowing good access of electrolyte to the dye, thereby assisting in dye regeneration (enhanced charge transfer). Pre‐treatment of the TiO2 electrodes reduced recombination at the fluorine‐doped tin oxide (FTO)/electrolyte interface. The post‐treatment study showed enhanced surface roughness through the deposition of a thin overlayer of amorphous TiO2 on the film structure. This led to a notable improvement in both dye adsorption and inherent light scattering effects by the TiO2 aggregates, resulting in enhanced energy harvesting. The thin TiO2 overlayer also acted as a barrier in a core‐shell configuration within the porous TiO2 matrix, and thereby reduced recombination. This allowed the hierarchical macro‐ and mesoporosity of the film matrix to be utilized more effectively for enhanced charge transfer during dye regeneration. Post‐treatment of the aggregated TiO2 matrix resulted in a 36% enhancement in power conversion efficiency from 4.41% of untreated cells to 6.01%.

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EIS analysis on low temperature fabrication of TiO2 porous films for dye-sensitized solar cells

Cited by 235 publications

References 22 publications

Test of Different Sensitizing Dyes in Dye-Sensitized Solar Cells Based on Nb2O5 Photoanodes

Test of Different Sensitizing Dyes in Dye-Sensitized Solar Cells Based on Nb2O5 Photoanodes

TiO₂‐Coated Multilayered SnO₂ Hollow Microspheres for Dye‐Sensitized Solar Cells

Improving Microstructured TiO₂ Photoanodes for Dye Sensitized Solar Cells by Simple Surface Treatment

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EIS analysis on low temperature fabrication of TiO2 porous films for dye-sensitized solar cells

Cited by 235 publications

References 22 publications

Test of Different Sensitizing Dyes in Dye-Sensitized Solar Cells Based on Nb2O5 Photoanodes

Test of Different Sensitizing Dyes in Dye-Sensitized Solar Cells Based on Nb2O5 Photoanodes

TiO2‐Coated Multilayered SnO2 Hollow Microspheres for Dye‐Sensitized Solar Cells

Improving Microstructured TiO2 Photoanodes for Dye Sensitized Solar Cells by Simple Surface Treatment

Contact Info

Product

Resources

About

TiO₂‐Coated Multilayered SnO₂ Hollow Microspheres for Dye‐Sensitized Solar Cells

Improving Microstructured TiO₂ Photoanodes for Dye Sensitized Solar Cells by Simple Surface Treatment