Electrical Resistance of AgTS鈥揝(CH2)n鈭?CH3//Ga2O3/EGaIn Tunneling Junctions

详细信息    查看全文

• 作者：Ludovico Cademartiri ; Martin M. Thuo ; Christian A. Nijhuis ; William F. Reus ; Simon Tricard ; Jabulani R. Barber ; Rana N. S. Sodhi ; Peter Brodersen ; Choongik Kim ; Ryan C. Chiechi ; George M. Whitesides
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：May 24, 2012
• 年：2012
• 卷：116
• 期：20
• 页码：10848-10860
• 全文大小：646K
• 年卷期：v.116,no.20(May 24, 2012)
• ISSN：1932-7455

文摘

Tunneling junctions having the structure Ag^TS鈥揝(CH₂)_n鈭?CH₃//Ga₂O₃/EGaIn allow physical鈥搊rganic studies of charge transport across self-assembled monolayers (SAMs). In ambient conditions, the surface of the liquid metal electrode (EGaIn, 75.5 wt % Ga, 24.5 wt % In, mp 15.7 掳C) oxidizes and adsorbs鈥昹ike other high-energy surfaces鈥昦dventitious contaminants. The interface between the EGaIn and the SAM thus includes a film of metal oxide, and probably also organic material adsorbed on this film; this interface will influence the properties and operation of the junctions. A combination of structural, chemical, and electrical characterizations leads to four conclusions about Ag^TS鈥揝(CH₂)_n鈭?CH₃//Ga₂O₃/EGaIn junctions. (i) The oxide is 0.7 nm thick on average, is composed mostly of Ga₂O₃, and appears to be self-limiting in its growth. (ii) The structure and composition (but not necessarily the contact area) of the junctions are conserved from junction to junction. (iii) The transport of charge through the junctions is dominated by the alkanethiolate SAM and not by the oxide or by the contaminants. (iv) The interface between the oxide and the eutectic alloy is rough at the micrometer scale.