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Improved conversion efficiency of Ag2S quantum dot-sensitized solar cells based on TiO2 nanotubes with a ZnO recombination barrier layer.

Chen C, Xie Y, Ali G, Yoo SH, Cho SO - Nanoscale Res Lett (2011)

Bottom Line: We improve the conversion efficiency of Ag2S quantum dot (QD)-sensitized TiO2 nanotube-array electrodes by chemically depositing ZnO recombination barrier layer on plain TiO2 nanotube-array electrodes.It is found that for the prepared electrodes, with increasing the cycles of Ag2S deposition, the photocurrent density and the conversion efficiency increase.In addition, as compared to the Ag2S QD-sensitized TiO2 nanotube-array electrode without the ZnO layers, the conversion efficiency of the electrode with the ZnO layers increases significantly due to the formation of efficient recombination layer between the TiO2 nanotube array and electrolyte.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong, Yuseong, Daejeon 305-701, Republic of Korea. socho@kaist.ac.kr.

ABSTRACT
We improve the conversion efficiency of Ag2S quantum dot (QD)-sensitized TiO2 nanotube-array electrodes by chemically depositing ZnO recombination barrier layer on plain TiO2 nanotube-array electrodes. The optical properties, structural properties, compositional analysis, and photoelectrochemistry properties of prepared electrodes have been investigated. It is found that for the prepared electrodes, with increasing the cycles of Ag2S deposition, the photocurrent density and the conversion efficiency increase. In addition, as compared to the Ag2S QD-sensitized TiO2 nanotube-array electrode without the ZnO layers, the conversion efficiency of the electrode with the ZnO layers increases significantly due to the formation of efficient recombination layer between the TiO2 nanotube array and electrolyte.

No MeSH data available.


UV-vis absorption spectrum of the plain TNT, ZnO/TNT, Ag2S(n)/TNT, and Ag2S(n)/ZnO/TNT films. n = 2, 4 and 8.
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Figure 4: UV-vis absorption spectrum of the plain TNT, ZnO/TNT, Ag2S(n)/TNT, and Ag2S(n)/ZnO/TNT films. n = 2, 4 and 8.

Mentions: Figure 4 shows optical absorption of annealed TNTs, ZnO/TNTs, and Ag2S(n)/ZnO/TNTs (n = 2, 4, and 8). It can be seen from Figure 4 that both plain TNTs and ZnO/TNTs absorb mainly UV light with wavelengths smaller than 400 nm. However, for the ZnO/TNT film, the absorbance of the spectra slightly increases compared to that for plain TNTs, suggesting the formation of ZnO thin film on TNTs. This result is similar to that for ZnO-coated TiO2 films in DSSCs [29], which can be attributed to the absorption of the ZnO layers coated on TNTs. After Ag2S deposition, the absorbance of the Ag2S(n)/ZnO/TNT films increases with the cycles of Ag2S chemical bath deposition process. Moreover, a significant shift of the spectral photoresponse is observed in the Ag2S(n)/ZnO/TNT films, indicating that the Ag2S deposits can be used to sensitize TiO2 nanotube arrays with respect to lower energy (longer wavelength) region of the sunlight. In addition, the absorbance increases with the increase in the cycles of Ag2S deposition, resulting from an increased amount of Ag2S nanoparticles.


Improved conversion efficiency of Ag2S quantum dot-sensitized solar cells based on TiO2 nanotubes with a ZnO recombination barrier layer.

Chen C, Xie Y, Ali G, Yoo SH, Cho SO - Nanoscale Res Lett (2011)

UV-vis absorption spectrum of the plain TNT, ZnO/TNT, Ag2S(n)/TNT, and Ag2S(n)/ZnO/TNT films. n = 2, 4 and 8.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211883&req=5

Figure 4: UV-vis absorption spectrum of the plain TNT, ZnO/TNT, Ag2S(n)/TNT, and Ag2S(n)/ZnO/TNT films. n = 2, 4 and 8.
Mentions: Figure 4 shows optical absorption of annealed TNTs, ZnO/TNTs, and Ag2S(n)/ZnO/TNTs (n = 2, 4, and 8). It can be seen from Figure 4 that both plain TNTs and ZnO/TNTs absorb mainly UV light with wavelengths smaller than 400 nm. However, for the ZnO/TNT film, the absorbance of the spectra slightly increases compared to that for plain TNTs, suggesting the formation of ZnO thin film on TNTs. This result is similar to that for ZnO-coated TiO2 films in DSSCs [29], which can be attributed to the absorption of the ZnO layers coated on TNTs. After Ag2S deposition, the absorbance of the Ag2S(n)/ZnO/TNT films increases with the cycles of Ag2S chemical bath deposition process. Moreover, a significant shift of the spectral photoresponse is observed in the Ag2S(n)/ZnO/TNT films, indicating that the Ag2S deposits can be used to sensitize TiO2 nanotube arrays with respect to lower energy (longer wavelength) region of the sunlight. In addition, the absorbance increases with the increase in the cycles of Ag2S deposition, resulting from an increased amount of Ag2S nanoparticles.

Bottom Line: We improve the conversion efficiency of Ag2S quantum dot (QD)-sensitized TiO2 nanotube-array electrodes by chemically depositing ZnO recombination barrier layer on plain TiO2 nanotube-array electrodes.It is found that for the prepared electrodes, with increasing the cycles of Ag2S deposition, the photocurrent density and the conversion efficiency increase.In addition, as compared to the Ag2S QD-sensitized TiO2 nanotube-array electrode without the ZnO layers, the conversion efficiency of the electrode with the ZnO layers increases significantly due to the formation of efficient recombination layer between the TiO2 nanotube array and electrolyte.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong, Yuseong, Daejeon 305-701, Republic of Korea. socho@kaist.ac.kr.

ABSTRACT
We improve the conversion efficiency of Ag2S quantum dot (QD)-sensitized TiO2 nanotube-array electrodes by chemically depositing ZnO recombination barrier layer on plain TiO2 nanotube-array electrodes. The optical properties, structural properties, compositional analysis, and photoelectrochemistry properties of prepared electrodes have been investigated. It is found that for the prepared electrodes, with increasing the cycles of Ag2S deposition, the photocurrent density and the conversion efficiency increase. In addition, as compared to the Ag2S QD-sensitized TiO2 nanotube-array electrode without the ZnO layers, the conversion efficiency of the electrode with the ZnO layers increases significantly due to the formation of efficient recombination layer between the TiO2 nanotube array and electrolyte.

No MeSH data available.