Ambipolar Organic Thin Film Transistor-like Behavior of Cationic and Anionic Phthalocyanines Fabricated Using Layer-by-Layer Deposition from Aqueous Solution

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• 作者：Jason Locklin ; Kazunari Shinbo ; Ken Onishi ; Futao Kaneko ; Zhenan Bao ; and Rigoberto C. Advincula
• 刊名：Chemistry of Materials
• 出版年：2003
• 出版时间：April 8, 2003
• 年：2003
• 卷：15
• 期：7
• 页码：1404 - 1412
• 全文大小：454K
• 年卷期：v.15,no.7(April 8, 2003)
• ISSN：1520-5002

文摘

Organic thin film field effect transistors of water-soluble cationic and anionic phthalocyanine derivatives were successfully prepared using the layer-by-layer deposition technique.The alternating film growth and subsequent transistor properties were studied with a varietyof techniques including ellipsometry, UV-vis spectroscopy, polarized UV-vis spectroscopy,AFM, and field effect transistor measurements. A stepwise and regular deposition ofcopper(II) phthalocyanine tetrakis(methyl pyridinium) chloride and copper(II) phthalocyaninetetrasulfonic acid, tetrasodium salt multilayers in both pure water and 0.03 M NaCl solutionwas observed. Differences in linear growth were observed between pure water and 0.03 MNaCl-based solutions. Polarized UV-vis spectra indicated that the conjugated phthalocyaninering lies almost flat on the substrate surface with a random orientation within the plane ofthe substrate. Unusual "ambipolar" transistor-like behavior was found for the films thatcan be attributed to an ion-modulated electrical conduction mechanism, which relies on theassistance of mobile ions to stabilize the oxidized or reduced species in the channel region.