title: Patterning Superatom Dopants on Transition Metal Dichalcogenides.
abstract: This study describes a new and simple approach to dope two-dimensional transition metal dichalcogenides (TMDCs) using the superatom Co6Se8(PEt3)6 as the electron dopant. Semiconducting TMDCs are wired into field-effect transistor devices and then immersed into a solution of these superatoms. The degree of doping is determined by the concentration of the superatoms in solution and by the length of time the films are immersed in the dopant solution. Using this chemical approach, we are able to turn mono- and few-layer MoS2 samples from moderately to heavily electron-doped states. The same approach applied on WSe2 films changes their characteristics from hole transporting to electron transporting. Moreover, we show that the superatom doping can be patterned on specific areas of TMDC films. To illustrate the power of this technique, we demonstrate the fabrication of a lateral p-n junction by selectively doping only a portion of the channel in a WSe2 device. Finally, encapsulation of the doped films with crystalline hydrocarbon layers stabilizes their properties in an ambient environment.
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Jaeeun
authors.initials: J
authors.lastname: Yu
authors.affiliation: KU-KIST Graduate School of Converging Science and Technology, Korea University , Seoul 136-701, Korea.
authors.forename: Chul-Ho
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Delphine
authors.initials: D
authors.lastname: Bouilly
authors.affiliation: Department of Applied Physics and Applied Mathematics, Columbia University , New York, New York 10027, United States.
authors.forename: Minyong
authors.initials: M
authors.lastname: Han
authors.affiliation: Department of Physics, Harvard University , Cambridge, Massachusetts 02138, United States.
authors.forename: Philip
authors.initials: P
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Steigerwald
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Xavier
authors.initials: X
authors.lastname: Roy
authors.affiliation: Department of Chemistry, Columbia University , New York, New York 10027, United States.
authors.forename: Colin
authors.initials: C
authors.lastname: Nuckolls
keywords: Transition metal dichalcogenide; chemical doping; encapsulation; lateral junction; superatom