Quantum Dot–Carbon Nanotube Hybrid Phototransistor with an Enhanced Optical Stark Effect

Authors

  • Chandan Biswas,

    1. WCU Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea
    Current affiliation:
    1. Device Research Lab, Department of Electrical Engineering, University of California, Los Angeles, CA 90095, USA
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  • Hyun Jeong,

    1. Center for Integrated Nanostructure Physics, Institute of Basic Science, WCU Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea
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  • Mun Seok Jeong,

    Corresponding author
    1. Center for Integrated Nanostructure Physics, Institute of Basic Science, WCU Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea
    • Center for Integrated Nanostructure Physics, Institute of Basic Science, WCU Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
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  • Woo Jong Yu,

    1. Department of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea
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  • Didier Pribat,

    1. WCU Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea
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  • Young Hee Lee

    Corresponding author
    1. Center for Integrated Nanostructure Physics, Institute of Basic Science, WCU Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea
    • Center for Integrated Nanostructure Physics, Institute of Basic Science, WCU Department of Energy Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
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Abstract

Enhanced carrier–carrier interactions in hybrid nanostructures exhibit exceptional electronic and optoelectronic properties. Carbon nanotubes demonstrate excellent switching behavior with high on/off ratio and high mobility but do not show photoresponse in the visible range, whereas quantum dots (QDs) shows excellent optical response in various optical ranges which can be tuned with diameter. Here, a simple and effective way to develop hybrid phototransistors with extraordinary optoelectronic properties is presented by decorating semiconducting QDs on the surface of a single-walled carbon nanotube (SWCNT). This hybrid structure demonstrates clear negative photoresponse and optical switching behavior, which could be further tuned by applying external gate bias in the future. A clear type conversion of SWCNT transistor from p-type to n-type caused by a charge transfer from attached QDs to CNT is demonstrated. Moreover, this hybrid structure also demonstrates an enhancement in ‘optical Stark effect’ without applying any external electric field. Charged SWCNT surface plays a key role behind the enhancement of optical Stark effect in QDs. The carrier dynamics of the QD and CNT heterostructures system highlights the potential application opportunity of the quantum dot systems, which can be adaptable to the current technologies.

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