title: Electron Excess Doping and Effective Schottky Barrier Reduction on the MoS2/h-BN Heterostructure.
abstract: Layered hexagonal boron nitride (h-BN) thin film is a dielectric that surpasses carrier mobility by reducing charge scattering with silicon oxide in diverse electronics formed with graphene and transition metal dichalcogenides. However, the h-BN effect on electron doping concentration and Schottky barrier is little known. Here, we report that use of h-BN thin film as a substrate for monolayer MoS2can induce ∼6.5 × 1011cm-2electron doping at room temperature which was determined using theoretical flat band model and interface trap density. The saturated excess electron concentration of MoS2on h-BN was found to be ∼5 × 1013cm-2at high temperature and was significantly reduced at low temperature. Further, the inserted h-BN enables us to reduce the Coulombic charge scattering in MoS2/h-BN and lower the effective Schottky barrier height by a factor of 3, which gives rise to four times enhanced the field-effect carrier mobility and an emergence of metal-insulator transition at a much lower charge density of ∼1.0 × 1012cm-2(T = 25 K). The reduced effective Schottky barrier height in MoS2/h-BN is attributed to the decreased effective work function of MoS2arisen from h-BN induced n-doping and the reduced effective metal work function due to dipole moments originated from fixed charges in SiO2.
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.
authors.forename: Min-Kyu
authors.initials: MK
authors.lastname: Joo
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.
authors.forename: Byoung Hee
authors.initials: BH
authors.lastname: Moon
authors.affiliation: Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Hyunjin
authors.initials: H
authors.lastname: Ji
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.
authors.forename: Gang Hee
authors.initials: GH
authors.lastname: Han
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Kim
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Gwanmu
authors.initials: G
authors.lastname: Lee
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Seong Chu
authors.initials: SC
authors.lastname: Lim
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Dongseok
authors.initials: D
authors.lastname: Suh
authors.affiliation: Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS) , Suwon 16419, Republic of Korea.|Department of Energy Science, Sungkyunkwan University , Suwon 16419, Republic of Korea.
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Lee
keywords: Coulomb scattering; MoS2; Schottky barrier height; dipole alignment; h-BN; interface trap density; substrate doping