Nanocrystal-mediated charge screening effects in nanowire field-effect transistors

C. J. Yoon, D. H. Yeom, D. Y. Jeong, M. G. Lee, B. M. Moon, S. S. Kim, C. Y. Choi, S. M. Koo

    Research output: Contribution to journalArticlepeer-review

    3 Citations (Scopus)

    Abstract

    ZnO nanowire field-effect transistors having an omega-shaped floating gate (OSFG) have been successfully fabricated by directly coating CdTe nanocrystals (∼6±2.5 nm) at room temperature, and compared to simultaneously prepared control devices without nanocrystals. Herein, we demonstrate that channel punchthrough may occur when the depletion from the OSFG takes place due to the trapped charges in the nanocrystals. Electrical measurements on the OSFG nanowire devices showed static-induction transistorlike behavior in the drain output IDS - VDS characteristics and a hysteresis window as large as ∼3.1 V in the gate transfer IDS - VGS characteristics. This behavior is ascribed to the presence of the CdTe nanocrystals, and is indicative of the trapping and emission of electrons in the nanocrystals. The numerical simulations clearly show qualitatively the same characteristics as the experimental data and confirm the effect, showing that the change in the potential distribution across the channel, induced by both the wrapping-around gate and the drain, affects the transport characteristics of the device. The cross-sectional energy band and potential profile of the OSFG channel corresponding to the "programed (noncharged)" and "erased (charged)" operations for the device are also discussed on the basis of the numerical capacitance-voltage simulations.

    Original languageEnglish
    Article number064503
    JournalJournal of Applied Physics
    Volume105
    Issue number6
    DOIs
    Publication statusPublished - 2009

    Bibliographical note

    Funding Information:
    This work was supported by the National R&D Project for Nano Science and Technology (Contract No. 10022916-2006-22), the Center for Integrated-Nano-Systems (CINS) of the Korea Research Foundation (Contract No. KRF-2006-005-J03601), the “SystemIC2010” project of the Korea Ministry of Commerce, Industry and Energy, the Korea Science and Engineering Foundation (KOSEF) through the National Research Laboratory Program [Contract No. R0A-2005-000-10045-02 (2007)], and the Nano R&D Program (Contract No. M10703000980-07M0300-98010); program funded by the Ministry of Science and Technology (Contract No. M10500000045-06J0000-04510), the Korea Research Foundation Grant fund (Grant No. KRF-2007-3310173), and the Research Grant of Kwangwoon University in 2008.

    ASJC Scopus subject areas

    • General Physics and Astronomy

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