Hydrolysis Improves Packing Density of Bromine-Terminated Alkyl-Chain, Silicon−Carbon Monolayers Linked to Silicon

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• 作者：Yaron S. Cohen ; Ayelet Vilan ; Izhar Ron ; David Cahen
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：April 16, 2009
• 年：2009
• 卷：113
• 期：15
• 页码：6174-6181
• 全文大小：329K
• 年卷期：v.113,no.15(April 16, 2009)
• ISSN：1932-7455

文摘

Bromine-terminated alkyl-chain monolayers, bound to oxide-free Si substrates, were prepared by self-assembly. Infrared spectroscopy and atomic force microscopy imply that monolayer packing density improves after hydrolysis, despite an increase in the presence of oxide. The probable reason is that OH-mediated intermolecular H-bonding along the monolayer emerges after hydrolysis and rearranges the molecular components of the insulating layer. Current−voltage and differential capacitance measurements show that also the interfacial electronic properties of these junctions are changed by hydrolysis of the Br groups. This is expressed in an increased effective Schottky barrier height and a decreased junction ideality factor. We correlate the proposed structural changes of the monolayer with the change in the interfacial electronic properties, with the help of the inhomogeneous Schottky barrier height model. The role of oxide in the charge transport through the monolayer is discussed, as well.