Electrical and Optical Characterization of MoS2 with Sulfur Vacancy Passivation by Treatment with Alkanethiol Molecules.
We investigated the physical properties of molybdenum disulfide (MoS2) atomic crystals with a sulfur vacancy passivation after treatment with alkanethiol molecules including their electrical, Raman, and photoluminescence (PL) characteristics. MoS2, one of the transition metal dichalcogenide materials, is a promising two-dimensional semiconductor material with good physical properties. It is known that sulfur vacancies exist in MoS2, resulting in the n-type behavior of MoS2. The sulfur vacancies on the MoS2 surface tend to form covalent bonds with sulfur-containing groups. In this study, we deposited alkanethiol molecules on MoS2 field effect transistors (FETs) and then characterized the electrical properties of the devices before and after the alkanethiol treatment. We observed that the electrical characteristics of MoS2 FETs dramatically changed after the alkanethiol treatment. We also observed that the Raman and PL spectra of MoS2 films changed after the alkanethiol treatment. These effects are attributed to the thiol (-SH) end groups in alkanethiols bonding at sulfur vacancy sites, thus altering the physical properties of the MoS2. This study will help us better understand the electrical and optical properties of MoS2 and suggest a way of tailoring the properties of MoS2 by passivating a sulfur vacancy with thiol molecules.
Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University , Seoul 151-744, Korea.
Kyungjune
K
Cho
Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University , Seoul 151-744, Korea.
Misook
M
Min
Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University , Seoul 151-744, Korea.
Tae-Young
TY
Kim
Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University , Seoul 151-744, Korea.
Hyunhak
H
Jeong
Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University , Seoul 151-744, Korea.
Jinsu
J
Pak
Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University , Seoul 151-744, Korea.
Jae-Keun
JK
Kim
Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University , Seoul 151-744, Korea.
Jingon
J
Jang
IBS Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 440-746, Korea.
Seok Joon
SJ
Yun
IBS Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University , Suwon 440-746, Korea.
Young Hee
YH
Lee
Jeonju Center, Korea Basic Science Institute , Jeonju, Jeollabuk-do 561-180, Korea.
Woong-Ki
WK
Hong
Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University , Seoul 151-744, Korea.
Takhee
T
Lee
electronic transport; field effect transistor; molecule adsorption; molybdenum disulfide