Limits...
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.


Preparation process of Ag2S quantum dot-sensitized ZnO/TNTs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211883&req=5

Figure 1: Preparation process of Ag2S quantum dot-sensitized ZnO/TNTs.

Mentions: The ZnO thin films on TNTs were prepared by using the successive ionic layer adsorption and reaction method, as described elsewhere [27,29]. Briefly, the annealed TNT electrodes were immersed in 0.01 M ZnCl2 solution complexed with an ammonia solution for 15 s and then in DI water at 92°C for 30 s, with the formation of solid ZnO layer. Finally, the as-prepared TNT electrodes were dried in air and annealed at 450°C for 30 min in air for better electrical continuity. Ag2S QDs were assembled on the crystallized TNT and ZnO/TNT electrodes by sequential chemical bath deposition (CBD) [25,30]. Typically, one CBD process was performed by dipping the plain TNT and ZnO/TNT electrodes in a 0.1 M AgNO3 ethanol solution at 25°C for 2 min, rinsing it with ethanol, and then dipped in a 0.1 M Na2S methanol solution for 2 min, followed by rinsing it again with methanol. The two-step dipping procedure is considered one CBD cycle. After several cycles, the sample became dark. In this study, 2, 4, and 8 cycles of Ag2S deposition were performed (denoted as Ag2S(2), Ag2S(4), and Ag2S(8), respectively). Finally, the as-prepared samples were dried in a N2 stream. The preparation process of as Ag2S-sensitized ZnO/TNT electrode is shown in Figure 1. For comparison, Ag2S-sensitized TNT electrodes without ZnO films were also fabricated by the same process.


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)

Preparation process of Ag2S quantum dot-sensitized ZnO/TNTs.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Preparation process of Ag2S quantum dot-sensitized ZnO/TNTs.
Mentions: The ZnO thin films on TNTs were prepared by using the successive ionic layer adsorption and reaction method, as described elsewhere [27,29]. Briefly, the annealed TNT electrodes were immersed in 0.01 M ZnCl2 solution complexed with an ammonia solution for 15 s and then in DI water at 92°C for 30 s, with the formation of solid ZnO layer. Finally, the as-prepared TNT electrodes were dried in air and annealed at 450°C for 30 min in air for better electrical continuity. Ag2S QDs were assembled on the crystallized TNT and ZnO/TNT electrodes by sequential chemical bath deposition (CBD) [25,30]. Typically, one CBD process was performed by dipping the plain TNT and ZnO/TNT electrodes in a 0.1 M AgNO3 ethanol solution at 25°C for 2 min, rinsing it with ethanol, and then dipped in a 0.1 M Na2S methanol solution for 2 min, followed by rinsing it again with methanol. The two-step dipping procedure is considered one CBD cycle. After several cycles, the sample became dark. In this study, 2, 4, and 8 cycles of Ag2S deposition were performed (denoted as Ag2S(2), Ag2S(4), and Ag2S(8), respectively). Finally, the as-prepared samples were dried in a N2 stream. The preparation process of as Ag2S-sensitized ZnO/TNT electrode is shown in Figure 1. For comparison, Ag2S-sensitized TNT electrodes without ZnO films were also fabricated by the same process.

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.