Probing the Surface Effect on Deep-Level Emissions of an Individual ZnO Nanowire via Spatially Resolved Cathodoluminescence

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• 作者：Haizhou Xue ; Nan Pan ; Rongguang Zeng ; Ming Li ; Xia Sun ; Zejun Ding ; Xiaoping Wang ; J. G. Hou
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：July 23, 2009
• 年：2009
• 卷：113
• 期：29
• 页码：12715-12718
• 全文大小：162K
• 年卷期：v.113,no.29(July 23, 2009)
• ISSN：1932-7455

文摘

Spatially resolved cathodoluminescence spectra are collected along the scanning positions of the electron beam across an individual hexagonally cross-sectioned ZnO nanowire to probe the surface effect on the deep-level (DL) emissions of the nanowire. A double-peak feature of DL emission intensity is observed in the intensity versus scanning position when the electron beam scans across the nanowire from one edge to the other. This spatial variation in DL intensity can be well-described by a simple core−shell model considering the strong surface effect. By further quasi-quantitative analysis and comparison with experimental results, we obtained an equivalent surface shell thickness of about 5−6 nm. The result unambiguously confirms that the surface effect plays a key role in the DL emission process of the nanowire, which should be carefully considered and cautiously modified for better performance of nanoscale functional materials and devices.