International Journal of Terahertz Science and Technology
  TST >> Vol.6, No.4, December 2013: PP. 234-248
 

(Invited paper) Terahertz spectroscopy study of carrier dynamics and transient photoconductivity in CdSSe nanobelts

Hongwei Liu 1, 2, # , Junpeng Lu 1, #, Minrui Zheng 1, Sing Hai Tang 1, Chorng Haur Sow 1*, and Xinhai Zhang 3*
1 Department of Physics, 2 Science Drive 3, National University of Singapore, Singapore 117542
2 Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602
3 Department of Electrical and Electronic Engineering, South University of Science and Technology of China, 1088 Xueyuan Road, Xili, Nanshan District, Shenzhen, Guangdong, China 518055
# These authors make equal contribution to this work.
*1 Email: physowch@nus.edu.sg, *3 Email: zhang.xh@sustc.edu.cn

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Abstract: We employ terahertz spectroscopy to investigate the carrier dynamics and transient photoconductivity in ternary CdSxSe1-x nanobelts. The photocarrier density and mobility are extracted by fitting the measured frequency-dependent complex photoconductivities with the Drude-Smith model. Surprisingly, ternary CdSxSe1-x nanobelts are found to exhibit higher photoconductivity than binary CdS and CdSe. This is attributed to higher photocarrier density in ternary compound. In addition, presence of Se in the samples results in prominent CdSe-like TO phonon mode due to electron-phonon interaction. The strength of this mode shows a large drop upon photoexcitation but recovers gradually with time. These results demonstrated that growth of ternary nanostructures can be utilized to alleviate the effects of high surface defects in nanostructures and improve their photoconductivity.

Keywords: Optical pump-THz probe Spectroscopy, CdSxSe1-x nanobelts, Photoconductivity

Received: 2013-11-29

Published: 2013-12-30

Cite this article:
Hongwei Liu, Junpeng Lu, Minrui Zheng, Sing Hai Tang, Chorng Haur Sow, and Xinhai Zhang.(Invited paper) Terahertz spectroscopy study of carrier dynamics and transient photoconductivity in CdSSe nanobelts[J]. International Journal of Terahertz Science and Technology, 2013, Vol.6, No.4: 223-233.  DOI:10.11906/TST.234-248.2013.12.17

URL: http://www.tstnetwork.org/10.11906/TST.234-248.2013.12.17

 
 
 

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