Nanochannel-Directed Growth of Multi-Segment Nanowire Heterojunctions of Metallic Au1鈥?i>xGex and Semiconducting Ge

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• 作者：Xiangdong Li ; Guowen Meng ; Shengyong Qin ; Qiaoling Xu ; Zhaoqin Chu ; Xiaoguang Zhu ; Mingguang Kong ; An-Ping Li
• 刊名：ACS Nano
• 出版年：2012
• 出版时间：January 24, 2012
• 年：2012
• 卷：6
• 期：1
• 页码：831-836
• 全文大小：389K
• 年卷期：v.6,no.1(January 24, 2012)
• ISSN：1936-086X

文摘

We report on the synthesis of multi-segment nanowire (NW) junctions of Au_1鈥?i>xGe_x and Ge inside the nanochannels of porous anodic aluminum oxide template. The one-dimensional heterostructures are grown with a low-temperature chemical vapor deposition process, assisted by electrodeposited Au nanowires (AuNWs). The Au-catalyzed vapor鈥搇iquid鈥搒olid growth process occurs simultaneously in multiple locations along the nanochannel, which leads to multi-segment Au_1鈥?i>xGe_x/Ge heterojunctions. The structures of the as-grown hybrid NWs, analyzed by using transmission electron microscopy and energy-dispersive X-ray spectroscopy elemental mapping, show clear compositional modulation with variable modulation period and controllable junction numbers. Remarkably, both GeNW and Au_1鈥?i>xGe_xNW segments are single crystalline with abrupt interfaces and good crystallographic coherences. The electronic and transport properties of individual NW junctions are measured by using a multi-probe scanning tunneling microscope, which confirms the semiconducting nature of Ge segments and the metallic behavior of Au_1鈥?i>xGe_x segments, respectively. The high yield of multiple segment NW junctions of a metal鈥搒emiconductor can facilitate the applications in nanoelectronics and optoelectronics that harness multiple functionalities of heterointerfaces.

Keywords:

germanium; gold; multiple segment hybrid nanowires; electrodeposition; chemical vapor deposition