title: MoS2-InGaZnO Heterojunction Phototransistors with Broad Spectral Responsivity.
abstract: We introduce an amorphous indium-gallium-zinc-oxide (a-IGZO) heterostructure phototransistor consisting of solution-based synthetic molybdenum disulfide (few-layered MoS2, with a band gap of ∼1.7 eV) and sputter-deposited a-IGZO (with a band gap of ∼3.0 eV) films as a novel sensing element with a broad spectral responsivity. The MoS2 and a-IGZO films serve as a visible light-absorbing layer and a high mobility channel layer, respectively. Spectroscopic measurements reveal that appropriate band alignment at the heterojunction provides effective transfer of the visible light-induced electrons generated in the few-layered MoS2 film to the underlying a-IGZO channel layer with a high carrier mobility. The photoresponse characteristics of the a-IGZO transistor are extended to cover most of the visible range by forming a heterojunction phototransistor that harnesses a visible light responding MoS2 film with a small band gap prepared through a large-area synthetic route. The MoS2-IGZO heterojunction phototransistors exhibit a photoresponsivity of approximately 1.7 A/W at a wavelength of 520 nm (an optical power of 1 μW) with excellent time-dependent photoresponse dynamics.
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University , Suwon 440-746, Republic of Korea.|Samsung-SKKU Graphene/2D Center, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Jaehyun
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Hyena
authors.initials: H
authors.lastname: Kwak
authors.affiliation: SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Youngbin
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Institute of Physics and Applied Physics, Yonsei University , Seoul 120-749, Republic of Korea.
authors.forename: Yu-Seon
authors.initials: YS
authors.lastname: Kang
authors.affiliation: Institute of Physics and Applied Physics, Yonsei University , Seoul 120-749, Republic of Korea.
authors.forename: Mann-Ho
authors.initials: MH
authors.lastname: Cho
authors.affiliation: Samsung-SKKU Graphene/2D Center, Sungkyunkwan University , Suwon 440-746, Republic of Korea.|SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University , Suwon 440-746, Republic of Korea.|School of Chemical Engineering, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Cho
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University , Suwon 440-746, Republic of Korea.|SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Yong-Hoon
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Device Laboratory, Device and System Research Center, Samsung Advanced Institute of Technology, Samsung Electronics Co. , Suwon 443-803, Republic of Korea.
authors.forename: Seong-Jun
authors.initials: SJ
authors.lastname: Jeong
authors.affiliation: Device Laboratory, Device and System Research Center, Samsung Advanced Institute of Technology, Samsung Electronics Co. , Suwon 443-803, Republic of Korea.
authors.forename: Seongjun
authors.initials: S
authors.lastname: Park
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University , Suwon 440-746, Republic of Korea.|SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Hoo-Jeong
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University , Suwon 440-746, Republic of Korea.|Samsung-SKKU Graphene/2D Center, Sungkyunkwan University , Suwon 440-746, Republic of Korea.
authors.forename: Hyoungsub
authors.initials: H
authors.lastname: Kim
keywords: InGaZnO; heterojunction; molybdenum disulfide; phototransistor; solution-based synthesis