title: Alloyed 2D Metal-Semiconductor Heterojunctions: Origin of Interface States Reduction and Schottky Barrier Lowering.
abstract: The long-term stability and superior device reliability through the use of delicately designed metal contacts with two-dimensional (2D) atomic-scale semiconductors are considered one of the critical issues related to practical 2D-based electronic components. Here, we investigate the origin of the improved contact properties of alloyed 2D metal-semiconductor heterojunctions. 2D WSe2-based transistors with mixed transition layers containing van der Waals (M-vdW, NbSe2/WxNb1-xSe2/WSe2) junctions realize atomically sharp interfaces, exhibiting long hot-carrier lifetimes of approximately 75,296 s (78 times longer than that of metal-semiconductor, Pd/WSe2 junctions). Such dramatic lifetime enhancement in M-vdW-junctioned devices is attributed to the synergistic effects arising from the significant reduction in the number of defects and the Schottky barrier lowering at the interface. Formation of a controllable mixed-composition alloyed layer on the 2D active channel would be a breakthrough approach to maximize the electrical reliability of 2D nanomaterial-based electronic applications.
authors.forename: Yonghun
authors.initials: Y
authors.lastname: Kim
authors.forename: Ah Ra
authors.initials: AR
authors.lastname: Kim
authors.affiliation: School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST) , 261 Cheomdan-gwangiro, Buk-Gu, Gwangju 61005, Republic of Korea.
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Yang
authors.affiliation: School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST) , 261 Cheomdan-gwangiro, Buk-Gu, Gwangju 61005, Republic of Korea.
authors.forename: Kyoung Eun
authors.initials: KE
authors.lastname: Chang
authors.forename: Jung-Dae
authors.initials: JD
authors.lastname: Kwon
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Choi
authors.affiliation: Structure Analysis Group, Gyeongbuk Science and Technology Promotion Center, Future Strategy Research Institute , 17 Cheomdangieop 1-ro, Sangdong-myeon, Gumi, Gyeongbuk 39171, Republic of Korea.
authors.forename: Jucheol
authors.initials: J
authors.lastname: Park
authors.forename: Kang Eun
authors.initials: KE
authors.lastname: Lee
authors.forename: Dong-Ho
authors.initials: DH
authors.lastname: Kim
authors.forename: Sung Mook
authors.initials: SM
authors.lastname: Choi
authors.forename: Kyu Hwan
authors.initials: KH
authors.lastname: Lee
authors.affiliation: School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST) , 261 Cheomdan-gwangiro, Buk-Gu, Gwangju 61005, Republic of Korea.
authors.forename: Byoung Hun
authors.initials: BH
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, Inha University , 100 Inharo, Nam-Gu, Incheon 22212, Republic of Korea.
authors.forename: Myung Gwan
authors.initials: MG
authors.lastname: Hahm
authors.forename: Byungjin
authors.initials: B
authors.lastname: Cho
keywords: 2D WSe2 field-effect transistor; Junction interface; Schottky barrier lowering; hot-carrier-induced degradation; interface trap density