Optical Cavity Effects in ZnO Nanowire Lasers and Waveguides
Co-sensitized quantum dot solar cell based on ZnO nanowire
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Co-sensitized quantum dot solar cell based on ZnO nanowire a. J. Chena, J. Wua, W. Leia, b. J.L. Songb, W.Q. Dengb, c. X.W. Sunc a School of Electronic Science and Engineering, Southeast University, Sipai Lou 2#, JinLing Yuan 109, Nanjing 210096, China b Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Science, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore c School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore Speaker ： H. C. Chen Advisor ： H. C. Kuo 1 Applied Surface Science 256 (2010) 7438–744
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Applied Surface Science 256 (2010) 7438–7441. Co-sensitized quantum dot solar cell based on ZnO nanowire. a School of Electronic Science and Engineering, Southeast University, Sipai Lou 2#, JinLing Yuan 109, Nanjing 210096, China - PowerPoint PPT Presentation
Transcript of Co-sensitized quantum dot solar cell based on ZnO nanowire
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Co-sensitized quantum dot solar cell based on ZnO nanowire
a. J. Chena, J. Wua, W. Leia, b. J.L. Songb, W.Q. Dengb, c. X.W. Sunc
a School of Electronic Science and Engineering, Southeast University, Sipai Lou 2#, JinLing Yuan 109, Nanjing 210096, Chinab Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Science, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singaporec School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore
Speaker： H. C. Chen Advisor： H. C. Kuo
Applied Surface Science 256 (2010) 7438–7441
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Outline
Introduction Experiment Results and Discussion Conclusions
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Introduction
CdS and CdSe QDs co-sensitized solar cell based on ZnO nanowire were studied in this work.
The co-sensitized structure has better performance than the single CdS or CdSe sensitized solar cell.
The power conversion efficiency of 1.42% is achieved for ZnO based CdS/CdSe co-sensitized solar cell
Electrochemical impedance spectroscopy (EIS) measured demonstrates that the electron lifetime for ZnO/CdS/CdSe (13.8 ms) is calculated longer than that of ZnO/CdS device (6.2 ms).
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Experiment
ZnO nanowire was grown by a hydrothermal method at 95 ◦C. The chemical bath deposition (CBD) method was used to assemble CdS QDs
onto ZnO film. ZnO film with CdS QDs immersed into pre-synthesized CdSe ethanol solution
for 6 h. The ZnO/CdS and ZnO/CdS/CdSe photoelectrodes were assembled with a 20
nm platinum-coated indium tin oxide (ITO) substrate as the counter electrode. They measured I-V curve , EQE , and EIS to analyze this cell.
electrolyteITO
Zno/Cds/CdSe
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Results and Discussion
It can be seen that the optical range of ZnO/CdS/CdSe is broader than ZnO/CdS and ZnO/CdSe.
Both the conduction and valence bands positions of the three materials increase in the order: ZnO < CdS < CdSe, which is benefit for the electrons to transfer.
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Results and Discussion – SEM & TEM
ZnO nanostructure consists of nanorod array on the bottom and the finer wires with 50nm in diameter and 9–10 µm length on the top.
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Results and Discussion – J-V curve
The higher performance of ZnO/CdS/CdSe is attributed to its broader light absorption range which leads to a higher photocurrent.
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Results and Discussion - EIS
The electron lifetime is calculated to be 6.2 and 13.8ms for ZnO/CdS and ZnO/CdS/CdSe device.
It is possibly due to the better coverage of ZnO/CdS/CdSe photoelectrode
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Conclusions
ZnO/CdS/CdSe has a better performance than ZnO/CdS, which is attributed to its broader light absorption range and better coverage of QDs on ZnO nanowires.
EIS measured demonstrated longer electron lifetime for ZnO/CdS/CdSe than ZnO/CdS.
A PCE of 1.42% was achieved for ZnO/CdS/CdSe, which accounts for 54% improvement compared to ZnO/CdS device.
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Thanks for your attention~
