Advances in Phytochemistry, Textile and Renewable Energy Research for
Industrial Growth – Nzila et al. (Eds)
© 2022 Copyright the Author(s), ISBN: 978-1-032-11871-0
Open Access: www.taylorfrancis.com, CC BY-NC-ND 4.0 license
Structural and electronic properties of light atom doped 2D MoS 2 :
Quantum mechanical study
Kibet Too Philemon ∗
Department of Physics, University of Nairobi, Nairobi, Kenya
Kiptiemoi Korir Kiprono
Department of Physics, Moi University, Eldoret, Kenya
Musembi J. Robinson
Department of Physics, University of Nairobi, Nairobi, Kenya
Jackson K. Cherutoi
Department of Chemistry and Biochemistry, Moi University, Eldoret, Kenya
ABSTRACT: 2D MoS 2 has been identified as a potential material for optoelectronic, energy, and environmental
applications. However, in pristine form its performance in the identified areas is lackluster and requires further
bandgap optimizations. It has been shown that non-metallic light atoms when introduced in 2D MoS 2 can modify
its electronic properties. In this work, we use density functional theory to study the effects of light atom dopants
on structural and electronic properties of 2D MoS 2 . It is found that O, Cl, P, and Se dopants can be introduced in
2D MoS 2 on S substitutional site under non-equilibrium growth conditions. It is noted that O and Cl substitutional
dopants on S site induce bandgap narrowing while P and Se induce bandgap broadening of 2D MoS 2 . While
co-dopants Cl-P, O-P, and O-Se induce bandgap reduction while Cl-Se broaden the bandgap. Therefore, with
proper dopant dosage, bandgap and electron carrier concentrations can be effectively moderated to suit various
applications.
Keywords: Molybdenum disulfide, Density functional theory, Doping, Semiconductors
1 INTRODUCTION
Electron carrier manipulation is essential for the
design and development of a new generation of solid
state devices based on 2D materials. The substitutional doping of the non-metal element in such systems
with an atom species with lower or higher valences
modifies the electron-carrier concentration of the 2D
host material. Such modifications allow for the creation of an atom-thick hetero-structure with potential applications in the photovoltaic and electronic
industries.
Molybdenum disulfide (MoS 2 ), silicene, and
graphene are some of the 2D materials that have
recently attracted intense interest due to their desirable electronic and optical properties that are ideal for
the development of nanoscale devices [1–5]. MoS 2
has been studied extensively due to its semiconductor character that allows for potential application in
nano-photonics, photo-voltaics, photo-catalysis, and
nano-electronics [6, 7]. Indeed, field effect transistors
∗ Corresponding author
based on 2D MoS 2 have demonstrated performance
comparable to those of silicon films and graphene
ribbons [8]. Recent studies have shown that phototransistors based on bilayer and monolayer MoS 2 have
limited sensitivity to various light spectrum such as
green, yellow, and yellow [8, 9], and the addition of
impurities tends to improve photo-response [10, 11].
The thermodynamically stable 2D MoS 2 is a semiconductor with a direct bandgap of 1.8 eV [12], which
can be moderated with the introduction of defects [14].
Indeed, it has been shown that non-metallic elements
such as carbon, hydrogen, boron, nitrogen, and fluorine can be used to substitute sulfur atoms in MoS 2 ,
which has an overall modification of the bandgap [15];
information derived from such studies can help guide
the experimental work in the fabrication of superior
devices. Desirable electronic and optical properties
observed in transition metal dichalcogenides can be
attributed to intrinsic defects formed during the synthesis process [16]. Recently, techniques for extrinsic
doping of MoS 2 have been developed, which showed
that the desirable character can be induced in host
DOI 10.1201/9781003221968-21
157
Industrial Growth – Nzila et al. (Eds)
© 2022 Copyright the Author(s), ISBN: 978-1-032-11871-0
Open Access: www.taylorfrancis.com, CC BY-NC-ND 4.0 license
Structural and electronic properties of light atom doped 2D MoS 2 :
Quantum mechanical study
Kibet Too Philemon ∗
Department of Physics, University of Nairobi, Nairobi, Kenya
Kiptiemoi Korir Kiprono
Department of Physics, Moi University, Eldoret, Kenya
Musembi J. Robinson
Department of Physics, University of Nairobi, Nairobi, Kenya
Jackson K. Cherutoi
Department of Chemistry and Biochemistry, Moi University, Eldoret, Kenya
ABSTRACT: 2D MoS 2 has been identified as a potential material for optoelectronic, energy, and environmental
applications. However, in pristine form its performance in the identified areas is lackluster and requires further
bandgap optimizations. It has been shown that non-metallic light atoms when introduced in 2D MoS 2 can modify
its electronic properties. In this work, we use density functional theory to study the effects of light atom dopants
on structural and electronic properties of 2D MoS 2 . It is found that O, Cl, P, and Se dopants can be introduced in
2D MoS 2 on S substitutional site under non-equilibrium growth conditions. It is noted that O and Cl substitutional
dopants on S site induce bandgap narrowing while P and Se induce bandgap broadening of 2D MoS 2 . While
co-dopants Cl-P, O-P, and O-Se induce bandgap reduction while Cl-Se broaden the bandgap. Therefore, with
proper dopant dosage, bandgap and electron carrier concentrations can be effectively moderated to suit various
applications.
Keywords: Molybdenum disulfide, Density functional theory, Doping, Semiconductors
1 INTRODUCTION
Electron carrier manipulation is essential for the
design and development of a new generation of solid
state devices based on 2D materials. The substitutional doping of the non-metal element in such systems
with an atom species with lower or higher valences
modifies the electron-carrier concentration of the 2D
host material. Such modifications allow for the creation of an atom-thick hetero-structure with potential applications in the photovoltaic and electronic
industries.
Molybdenum disulfide (MoS 2 ), silicene, and
graphene are some of the 2D materials that have
recently attracted intense interest due to their desirable electronic and optical properties that are ideal for
the development of nanoscale devices [1–5]. MoS 2
has been studied extensively due to its semiconductor character that allows for potential application in
nano-photonics, photo-voltaics, photo-catalysis, and
nano-electronics [6, 7]. Indeed, field effect transistors
∗ Corresponding author
based on 2D MoS 2 have demonstrated performance
comparable to those of silicon films and graphene
ribbons [8]. Recent studies have shown that phototransistors based on bilayer and monolayer MoS 2 have
limited sensitivity to various light spectrum such as
green, yellow, and yellow [8, 9], and the addition of
impurities tends to improve photo-response [10, 11].
The thermodynamically stable 2D MoS 2 is a semiconductor with a direct bandgap of 1.8 eV [12], which
can be moderated with the introduction of defects [14].
Indeed, it has been shown that non-metallic elements
such as carbon, hydrogen, boron, nitrogen, and fluorine can be used to substitute sulfur atoms in MoS 2 ,
which has an overall modification of the bandgap [15];
information derived from such studies can help guide
the experimental work in the fabrication of superior
devices. Desirable electronic and optical properties
observed in transition metal dichalcogenides can be
attributed to intrinsic defects formed during the synthesis process [16]. Recently, techniques for extrinsic
doping of MoS 2 have been developed, which showed
that the desirable character can be induced in host
DOI 10.1201/9781003221968-21
157