Limits...
Ag nanoparticle-deposited TiO2 nanotube arrays for electrodes of Dye-sensitized solar cells.

Kawamura G, Ohmi H, Tan WK, Lockman Z, Muto H, Matsuda A - Nanoscale Res Lett (2015)

Bottom Line: Efficient charge transportation through the ordered nanostructure of TNT arrays should be carried out compared to conventional particulate TiO2 electrodes.In this work, we deposited Ag nanoparticles (NPs) on the wall of TNT arrays to enhance light-harvesting property.Dye-sensitized solar cells with these Ag NP-deposited TNT arrays yielded a higher power conversion efficiency (2.03 %) than those without Ag NPs (1.39 %). 06.60.Ei Sample preparation, 81.05.Bx Metals, Semimetals, Alloys, 81.07.De Nanotubes.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, 441-8580 Aichi Japan.

ABSTRACT

Abstract: Dye-sensitized solar cells composed of a photoanode of Ag nanoparticle (NP)-deposited TiO2 nanotube (TNT) arrays were fabricated. The TNT arrays were prepared by anodizing Ti films on fluorine-doped tin oxide (FTO)-coated glass substrates. Efficient charge transportation through the ordered nanostructure of TNT arrays should be carried out compared to conventional particulate TiO2 electrodes. However, it has been a big challenge to grow TNT arrays on FTO glass substrates with the lengths needed for sufficient light-harvesting (tens of micrometers). In this work, we deposited Ag nanoparticles (NPs) on the wall of TNT arrays to enhance light-harvesting property. Dye-sensitized solar cells with these Ag NP-deposited TNT arrays yielded a higher power conversion efficiency (2.03 %) than those without Ag NPs (1.39 %).

Pacs codes: 06.60.Ei Sample preparation, 81.05.Bx Metals, Semimetals, Alloys, 81.07.De Nanotubes.

No MeSH data available.


Related in: MedlinePlus

XRD patterns of TNT arrays before and after heat treatment and subsequent Ag nanoparticle deposition (a). Cross-sectional TEM (b) and EDX mappings associated with the corresponding TEM image (c) of Ag nanoparticle deposited-TNT arrays
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4440869&req=5

Fig4: XRD patterns of TNT arrays before and after heat treatment and subsequent Ag nanoparticle deposition (a). Cross-sectional TEM (b) and EDX mappings associated with the corresponding TEM image (c) of Ag nanoparticle deposited-TNT arrays

Mentions: Figure 4a shows the XRD patterns of TNT arrays on FTO before and after heat treatment and subsequent Ag nanoparticle deposition. Peaks from FTO were only observed in the pattern of as-anodized TNT arrays. On the other hand, the heat-treated sample showed anatase peaks as well as FTO peaks in the XRD pattern. This indicated that amorphous TiO2 crystallized to become anatase TiO2 through annealing at 450 °C. It was also confirmed that the sheet resistance of FTO was not deteriorated by the heating process. A small peak of Ag appeared at ~44° after Ag nanoparticle deposition process. The dispersion state of deposited Ag was studied using TEM-EDX analyses. The cross-sectional TEM image of Ag nanoparticle-deposited TNT arrays (Fig. 4b) revealed that Ag was deposited as oval nanoparticles with minor axes of 10–50 nm, which were smaller than the pore diameter of TNTs (~50 nm). This means that the nanoparticles were deposited at the inside of the tubular pores of arrays. The TEM-EDX results (Fig. 4c) showed that Ag nanoparticles were preferentially deposited onto the upper part of the arrays, so the bottom part of them was almost empty. This state of Ag distribution was formed presumably because the TNTs were not fully filled with AgNO3 solution when Ag was deposited by UV radiation. However, the dispersion state of Ag in this sample is probably suitable to enhance DSSC performance because of the following two reasons: (i) if the arrays were fully covered with Ag, dye molecules could not be adsorbed on TiO2; (ii) surface plasmon resonance of Ag nanoparticles shows not only absorption but also scattering of light, thus the bottom part of TNT arrays should not be coated with Ag. Otherwise, certain amount of incident light is scattered by LSPR of Ag nanoparticles and not goes into DSSCs.Fig. 4


Ag nanoparticle-deposited TiO2 nanotube arrays for electrodes of Dye-sensitized solar cells.

Kawamura G, Ohmi H, Tan WK, Lockman Z, Muto H, Matsuda A - Nanoscale Res Lett (2015)

XRD patterns of TNT arrays before and after heat treatment and subsequent Ag nanoparticle deposition (a). Cross-sectional TEM (b) and EDX mappings associated with the corresponding TEM image (c) of Ag nanoparticle deposited-TNT arrays
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4440869&req=5

Fig4: XRD patterns of TNT arrays before and after heat treatment and subsequent Ag nanoparticle deposition (a). Cross-sectional TEM (b) and EDX mappings associated with the corresponding TEM image (c) of Ag nanoparticle deposited-TNT arrays
Mentions: Figure 4a shows the XRD patterns of TNT arrays on FTO before and after heat treatment and subsequent Ag nanoparticle deposition. Peaks from FTO were only observed in the pattern of as-anodized TNT arrays. On the other hand, the heat-treated sample showed anatase peaks as well as FTO peaks in the XRD pattern. This indicated that amorphous TiO2 crystallized to become anatase TiO2 through annealing at 450 °C. It was also confirmed that the sheet resistance of FTO was not deteriorated by the heating process. A small peak of Ag appeared at ~44° after Ag nanoparticle deposition process. The dispersion state of deposited Ag was studied using TEM-EDX analyses. The cross-sectional TEM image of Ag nanoparticle-deposited TNT arrays (Fig. 4b) revealed that Ag was deposited as oval nanoparticles with minor axes of 10–50 nm, which were smaller than the pore diameter of TNTs (~50 nm). This means that the nanoparticles were deposited at the inside of the tubular pores of arrays. The TEM-EDX results (Fig. 4c) showed that Ag nanoparticles were preferentially deposited onto the upper part of the arrays, so the bottom part of them was almost empty. This state of Ag distribution was formed presumably because the TNTs were not fully filled with AgNO3 solution when Ag was deposited by UV radiation. However, the dispersion state of Ag in this sample is probably suitable to enhance DSSC performance because of the following two reasons: (i) if the arrays were fully covered with Ag, dye molecules could not be adsorbed on TiO2; (ii) surface plasmon resonance of Ag nanoparticles shows not only absorption but also scattering of light, thus the bottom part of TNT arrays should not be coated with Ag. Otherwise, certain amount of incident light is scattered by LSPR of Ag nanoparticles and not goes into DSSCs.Fig. 4

Bottom Line: Efficient charge transportation through the ordered nanostructure of TNT arrays should be carried out compared to conventional particulate TiO2 electrodes.In this work, we deposited Ag nanoparticles (NPs) on the wall of TNT arrays to enhance light-harvesting property.Dye-sensitized solar cells with these Ag NP-deposited TNT arrays yielded a higher power conversion efficiency (2.03 %) than those without Ag NPs (1.39 %). 06.60.Ei Sample preparation, 81.05.Bx Metals, Semimetals, Alloys, 81.07.De Nanotubes.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, 441-8580 Aichi Japan.

ABSTRACT

Abstract: Dye-sensitized solar cells composed of a photoanode of Ag nanoparticle (NP)-deposited TiO2 nanotube (TNT) arrays were fabricated. The TNT arrays were prepared by anodizing Ti films on fluorine-doped tin oxide (FTO)-coated glass substrates. Efficient charge transportation through the ordered nanostructure of TNT arrays should be carried out compared to conventional particulate TiO2 electrodes. However, it has been a big challenge to grow TNT arrays on FTO glass substrates with the lengths needed for sufficient light-harvesting (tens of micrometers). In this work, we deposited Ag nanoparticles (NPs) on the wall of TNT arrays to enhance light-harvesting property. Dye-sensitized solar cells with these Ag NP-deposited TNT arrays yielded a higher power conversion efficiency (2.03 %) than those without Ag NPs (1.39 %).

Pacs codes: 06.60.Ei Sample preparation, 81.05.Bx Metals, Semimetals, Alloys, 81.07.De Nanotubes.

No MeSH data available.


Related in: MedlinePlus