Study on dynamics of photoexcited charge injection and trapping in CdS quantum dots sensitized TiO{sub 2} nanowire array film electrodes

The photoexcited electrons transfer dynamics of the CdS quantum dots (QDs) deposited in TiO{sub 2} nanowire array films are studied using surface photovoltage (SPV) and transient photovoltage (TPV) techniques. By comparing the SPV results with different thicknesses of QDs layers, we can separate the...

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Bibliographic Details
Published in:Applied physics letters 2014-05, Vol.104 (20)
Main Authors: Pang, Shan, Cheng, Ke, Yuan, Zhanqiang, Xu, Suyun, Cheng, Gang, Du, Zuliang
Format: Article
Language:English
Subjects:
CADMIUM SULFIDES
ELECTRODES
ELECTRON BEAM INJECTION
ELECTRON TRANSFER
INJECTION
LAYERS
NANOSCIENCE AND NANOTECHNOLOGY
NANOWIRES
PHOTOCURRENTS
PHOTOEMISSION
QUANTUM DOTS
THICKNESS
TITANIUM OXIDES
TRANSIENTS
TRAPPING
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Summary:The photoexcited electrons transfer dynamics of the CdS quantum dots (QDs) deposited in TiO{sub 2} nanowire array films are studied using surface photovoltage (SPV) and transient photovoltage (TPV) techniques. By comparing the SPV results with different thicknesses of QDs layers, we can separate the dynamic characteristics of photoexcited electrons injection and trapping. It is found that the TPV signals of photoexcited electrons trapped in the CdS QDs occur at timescales of about 2 × 10{sup −8} s, which is faster than that of the photoexcited electrons injected from CdS into TiO{sub 2}. More than 90 nm of the thickness of the CdS QDs layer will seriously affect the photoexcited electrons transfer and injection.
ISSN:0003-6951
1077-3118
DOI:10.1063/1.4879027