title: Ultrahigh Responsivity in Graphene-ZnO Nanorod Hybrid UV Photodetector.
abstract: Ultraviolet (UV) photodetectors based on ZnO nanostructure/graphene (Gr) hybrid-channel field-effect transistors (FETs) are investigated under illumination at various incident photon intensities and wavelengths. The time-dependent behaviors of hybrid-channel FETs reveal a high sensitivity and selectivity toward the near-UV region at the wavelength of 365 nm. The devices can operate at low voltage and show excellent selectivity, high responsivity (RI ), and high photoconductive gain (G). The change in the transfer characteristics of hybrid-channel FETs under UV light illumination allows to detect both photovoltage and photocurrent. The shift of the Dirac point (V Dirac ) observed during UV exposure leads to a clearer explanation of the response mechanism and carrier transport properties of Gr, and this phenomenon permits the calculation of electron concentration per UV power density transferred from ZnO nanorods and ZnO nanoparticles to Gr, which is 9 × 10(10) and 4 × 10(10) per mW, respectively. The maximum values of RI and G infer from the fitted curves of RI and G versus UV intensity are 3 × 10(5) A W(-1) and 10(6) , respectively. Therefore, the hybrid-channel FETs studied herein can be used as UV sensing devices with high performance and low power consumption, opening up new opportunities for future optoelectronic devices.
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, South Korea.
authors.forename: Vinh Quang
authors.initials: VQ
authors.lastname: Dang
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, South Korea.
authors.forename: Tran Quang
authors.initials: TQ
authors.lastname: Trung
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, South Korea.
authors.forename: Do-Il
authors.initials: DI
authors.lastname: Kim
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, South Korea.
authors.forename: Le Thai
authors.initials: le T
authors.lastname: Duy
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, South Korea.
authors.forename: Byeong-Ung
authors.initials: BU
authors.lastname: Hwang
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, South Korea.
authors.forename: Doo-Won
authors.initials: DW
authors.lastname: Lee
authors.affiliation: SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, South Korea.
authors.forename: Bo-Yeong
authors.initials: BY
authors.lastname: Kim
authors.affiliation: Department of Energy Science (DOES), Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, South Korea.
authors.forename: Le Duc
authors.initials: le D
authors.lastname: Toan
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, South Korea.|SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, South Korea.|Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, Suwon, Kyunggi-do, 440-746, South Korea.
authors.forename: Nae-Eung
authors.initials: NE
authors.lastname: Lee
keywords: ZnO nanorods; field-effect transistors; graphene; hybrid channels; photodetectors