title: Metallic conduction induced by direct anion site doping in layered SnSe2.
abstract: The emergence of metallic conduction in layered dichalcogenide semiconductor materials by chemical doping is one of key issues for two-dimensional (2D) materials engineering. At present, doping methods for layered dichalcogenide materials have been limited to an ion intercalation between layer units or electrostatic carrier doping by electrical bias owing to the absence of appropriate substitutional dopant for increasing the carrier concentration. Here, we report the occurrence of metallic conduction in the layered dichalcogenide of SnSe2 by the direct Se-site doping with Cl as a shallow electron donor. The total carrier concentration up to ~10(20) cm(-3) is achieved by Cl substitutional doping, resulting in the improved conductivity value of ~170 S · cm(-1) from ~1.7 S · cm(-1) for non-doped SnSe2. When the carrier concentration exceeds ~10(19) cm(-3), the conduction mechanism is changed from hopping to degenerate conduction, exhibiting metal-insulator transition behavior. Detailed band structure calculation reveals that the hybridized s-p orbital from Sn 5s and Se 4p states is responsible for the degenerate metallic conduction in electron-doped SnSe2.
authors.affiliation: Department of Materials Science and Engineering, The University of Seoul,, Seoul 130-743, South Korea.
authors.forename: Sang Il
authors.initials: SI
authors.lastname: Kim
authors.affiliation: Materials R&D Center, Samsung Advanced Institute of Technology, Suwon 443-370, Republic of Korea.
authors.forename: Sungwoo
authors.initials: S
authors.lastname: Hwang
authors.affiliation: Materials R&D Center, Samsung Advanced Institute of Technology, Suwon 443-370, Republic of Korea.
authors.forename: Se Yun
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Platform Technology Laboratory, Samsung Advanced Institute of Technology, Suwon 443-370, Republic of Korea.
authors.forename: Woo-Jin
authors.initials: WJ
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, The University of Seoul,, Seoul 130-743, South Korea.
authors.forename: Doh Won
authors.initials: DW
authors.lastname: Jung
authors.affiliation: Materials R&D Center, Samsung Advanced Institute of Technology, Suwon 443-370, Republic of Korea.
authors.forename: Kyoung-Seok
authors.initials: KS
authors.lastname: Moon
authors.affiliation: Department of Advanced Materials Engineering, Daejeon University, Daejeon 300-716, Republic of Korea.
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Materials R&D Center, Samsung Advanced Institute of Technology, Suwon 443-370, Republic of Korea.
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Cho
authors.affiliation: Platform Technology Laboratory, Samsung Advanced Institute of Technology, Suwon 443-370, Republic of Korea.
authors.forename: Yong-Hee
authors.initials: YH
authors.lastname: Cho
authors.affiliation: Platform Technology Laboratory, Samsung Advanced Institute of Technology, Suwon 443-370, Republic of Korea.
authors.forename: Jung-Hwa
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Platform Technology Laboratory, Samsung Advanced Institute of Technology, Suwon 443-370, Republic of Korea.
authors.forename: Dong-Jin
authors.initials: DJ
authors.lastname: Yun
authors.affiliation: Department of Nano Applied Engineering, Kangwon National University, Chooncheon 200-701, Republic of Korea.
authors.forename: Kyu Hyoung
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Materials R&D Center, Samsung Advanced Institute of Technology, Suwon 443-370, Republic of Korea.
authors.forename: In-taek
authors.initials: IT
authors.lastname: Han
authors.affiliation: Department of Physics, Kunsan National University, Gunsan 573-701, Republic of Korea.
authors.forename: Kimoon
authors.initials: K
authors.lastname: Lee
authors.affiliation: Materials R&D Center, Samsung Advanced Institute of Technology, Suwon 443-370, Republic of Korea.
authors.forename: Yoonchul
authors.initials: Y
authors.lastname: Sohn