title: Tuning Carrier Tunneling in van der Waals Heterostructures for Ultrahigh Detectivity.
abstract: Semiconducting transition metal dichalcogenides (TMDs) are promising materials for photodetection over a wide range of visible wavelengths. Photodetection is generally realized via a phototransistor, photoconductor, p-n junction photovoltaic device, and thermoelectric device. The photodetectivity, which is a primary parameter in photodetector design, is often limited by either low photoresponsivity or a high dark current in TMDs materials. Here, we demonstrated a highly sensitive photodetector with a MoS2/h-BN/graphene heterostructure, by inserting a h-BN insulating layer between graphene electrode and MoS2photoabsorber, the dark-carriers were highly suppressed by the large electron barrier (2.7 eV) at the graphene/h-BN junction while the photocarriers were effectively tunneled through small hole barrier (1.2 eV) at the MoS2/h-BN junction. With both high photocurrent/dark current ratio (>105) and high photoresponsivity (180 AW-1), ultrahigh photodetectivity of 2.6 × 1013Jones was obtained at 7 nm thick h-BN, about 100-1000 times higher than that of previously reported MoS2-based devices.
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Korea.
authors.forename: Quoc An
authors.initials: QA
authors.lastname: Vu
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Korea.
authors.forename: Jin Hee
authors.identifier: 0000-0002-6746-7508
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Korea.
authors.forename: Van Luan
authors.initials: VL
authors.lastname: Nguyen
authors.forename: Yong Seon
authors.initials: YS
authors.lastname: Shin
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Korea.
authors.forename: Seong Chu
authors.identifier: 0000-0002-0751-1458
authors.initials: SC
authors.lastname: Lim
authors.affiliation: Samsung Advanced Institute of Technology , Suwon, 16678, Korea.
authors.forename: Kiyoung
authors.initials: K
authors.lastname: Lee
authors.affiliation: Samsung Advanced Institute of Technology , Suwon, 16678, Korea.
authors.forename: Jinseong
authors.initials: J
authors.lastname: Heo
authors.affiliation: Samsung Advanced Institute of Technology , Suwon, 16678, Korea.
authors.forename: Seongjun
authors.initials: S
authors.lastname: Park
authors.affiliation: Korea Electronics Technology Institute , Seongnam, 13509, Republic of Korea.
authors.forename: Kunnyun
authors.initials: K
authors.lastname: Kim
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Korea.
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Lee
authors.forename: Woo Jong
authors.identifier: 0000-0002-7399-307X
authors.initials: WJ
authors.lastname: Yu
keywords: Two-dimensional material; heterostructure; hexagonal boron nitrite; high detectivity; molybdenum disulfide; photodetector