Electrical and Surface Properties of InAs/InSb Nanowires Cleaned by Atomic Hydrogen

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• 作者：James L. Webb ; Johan Knutsson ; Martin Hjort ; Sepideh Gorji Ghalamestani ; Kimberly A. Dick ; Rainer Timm ; Anders Mikkelsen
• 刊名：Nano Letters
• 出版年：2015
• 出版时间：August 12, 2015
• 年：2015
• 卷：15
• 期：8
• 页码：4865-4875
• 全文大小：628K
• ISSN：1530-6992

文摘

We present a study of InAs/InSb heterostructured nanowires by X-ray photoemission spectroscopy (XPS), scanning tunneling microscopy (STM), and in-vacuum electrical measurements. Starting with pristine nanowires covered only by the native oxide formed through exposure to ambient air, we investigate the effect of atomic hydrogen cleaning on the surface chemistry and electrical performance. We find that clean and unreconstructed nanowire surfaces can be obtained simultaneously for both InSb and InAs by heating to 380 卤 20 掳C under an H₂ pressure 2 脳 10^鈥? mbar. Through electrical measurement of individual nanowires, we observe an increase in conductivity of 2 orders of magnitude by atomic hydrogen cleaning, which we relate through theoretical simulation to the contact-nanowire junction and nanowire surface Fermi level pinning. Our study demonstrates the significant potential of atomic hydrogen cleaning regarding device fabrication when high quality contacts or complete control of the surface structure is required. As hydrogen cleaning has recently been shown to work for many different types of III鈥揤 nanowires, our findings should be applicable far beyond the present materials system.