Organization of Organic Molecules with Inorganic Nanoparticles: Hybrid Nanodiodes

Authors

  • Kallol Mohanta,

    1. Indian Association for the Cultivation of Science Department of Solid State Physics and Centre for Advanced Materials Kolkata 700032 (India)
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  • Sudip K. Batabyal,

    1. Indian Association for the Cultivation of Science Department of Solid State Physics and Centre for Advanced Materials Kolkata 700032 (India)
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  • Amlan J. Pal

    Corresponding author
    1. Indian Association for the Cultivation of Science Department of Solid State Physics and Centre for Advanced Materials Kolkata 700032 (India)
    • Indian Association for the Cultivation of Science Department of Solid State Physics and Centre for Advanced Materials Kolkata 700032 (India)
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  • K.M. acknowledges a CSIR Junior Research Fellowship No. 9/80(491)/2005-EMR-I, Roll No. 509342. The Department of Science and Technology, Government of India, financially supported the work through a Ramanna Fellowship SR/S2/RFCMP-02/2005. Supporting Information is available online from Wiley InterScience or from the author.

Abstract

A monolayer of inorganic nanoparticles and a monolayer of organic molecules have been electrostatically assembled in sequence. Such assemblies or organizations exhibit electrical rectification. When the sequence of the organization is reversed, the direction of rectification becomes opposite. In both n-type ZnO/organic and organic/n-ZnO assemblies, electron flow is favorable from the n-ZnO nanoparticle to the (electron-accepting) organic molecule. While the individual components do not show any rectification, substitutes of the organic molecule tune electrical rectification. Junctions between a p-type ZnO nanoparticle and an electron-donating metal phthalocyanine favor current flow in the nanoparticle-to-phthalocyanine direction. The rectification in a junction between a nanoparticle and an organic molecule is due to the parity between free carriers in the former component and the type of carrier-accepting nature in the latter one. By observing electrical rectification with the tip of a scanning tunneling microscope, organic/inorganic hybrid nanodiodes or rectifiers on the molecular/nanoscale have been established.

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