Photocurrent Generation in Noncovalently Assembled Multilayered Thin Films

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• 作者：Peter F. Driscoll ; Eugene F. Douglass ; Jr. ; Man Phewluangdee ; Ernesto R. Soto ; Christopher G. F. Cooper ; John C. MacDonald ; Christopher R. Lambert ; W. Grant McGimpsey
• 刊名：Langmuir
• 出版年：2008
• 出版时间：May 6, 2008
• 年：2008
• 卷：24
• 期：9
• 页码：5140 - 5145
• 全文大小：131K
• 年卷期：v.24,no.9(May 6, 2008)
• ISSN：1520-5827

文摘

Multilayered photocurrent generating thin films were fabricated by templated noncovalent assembly via stepwiseassembly of molecular components. Each of films I-IV contained an underlying self-assembled monolayer (SAM)consisting of an alkanethiol linked covalently to a 2,6-dicarboxypyridine ligand that served as a binding site forattaching additional molecular components. The SAM subsequently was functionalized by sequential deposition ofCu(II), Co(II), or Fe(III) ions followed by a variety of substituted 2,6-dicarboxypyridine ligands as a means to incorporateone or more layers of pyrene chromophores into the film. The films were characterized by contact angle measurements,ellipsometry, grazing incidence IR, cyclic voltammetry, and impedance spectroscopy after deposition of each layer,confirming the formation of ordered, stable layers. Following incorporation into a three-electrode system, photoexcitationresulted in the generation of a cathodic photocurrent in the presence of methyl viologen and an anodic photocurrentin the presence of triethanolamine. Using this strategy, systems were fabricated that produced up to 89 nA/cm² ofreproducible photocurrent.