Transient Photoconductivity of Ternary CdSSe Nanobelts As Measured by Time-Resolved Terahertz Spectroscopy

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• 作者：Junpeng Lu ; Hongwei Liu ; Sharon Xiaodai Lim ; Sing Hai Tang ; Chorng Haur Sow ; Xinhai Zhang
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：June 13, 2013
• 年：2013
• 卷：117
• 期：23
• 页码：12379-12384
• 全文大小：394K
• 年卷期：v.117,no.23(June 13, 2013)
• ISSN：1932-7455

文摘

The frequency- and fluence-dependent transient photoconductivity in ternary CdSSe nanobelts is investigated using time-resolved terahertz spectroscopy. The carrier density and mobility are extracted by modeling the measured complex photoconductivity using the Drude鈥揝mith model. Within the first few picoseconds of excitation, both the carrier density and mobility reach their maximum values and then decay gradually over tens to hundreds of picoseconds. The decay of free carriers is mainly attributed to fast surface trapping and structural-defect-mediated recombination. The surface trapping saturates rapidly with increasing excitation fluence attributable to the low trapping density on the nanobelt surface caused by self-passivation of surface defects during the growth process.