Pristine and holey graphene quantum dots: Optical properties using time independent and dependent density functional theory

Mohamed A. Abdelati; Mohamed M. Fadlallah; Yosr E.E.D. Gamal; Ahmed A. Maarouf

doi:10.1016/j.physe.2020.114602

Pristine and holey graphene quantum dots: Optical properties using time independent and dependent density functional theory

Mohamed A. Abdelati, Mohamed M. Fadlallah, Yosr E.E.D. Gamal, Ahmed A. Maarouf

Research output: Contribution to journal › Article › peer-review

16 Scopus citations

Abstract

The zero bandgap of graphene limits its utilization in optoelectronics. Quantum confinement in finite-size graphene structures, such as graphene quantum dots (GQDs) and holey GQDs, may offer a path for generating a wide range of HOMO-LUMO gaps. Edge terminations and pore passivations in these structures provide further means to alter their optical properties. In this work, we study the structural stabilities and optical properties of GQDs and holey GQDs with different sizes, edge terminations, and pore passivations, using density functional theory (DFT) as well as time dependent DFT. We find that the optical spectra of GQDs depend primarily on their size. Edge termination has a small influence on the spectra; shifting the absorption peaks by ~ 0.2 eV, which gets smaller for larger GQDs. Creation of pores in GQDs lead to the emergence of new peaks in their absorption spectra. Pore passivation seems to have the biggest effect on the absorption spectra of holey GQDs, while their termination leads to slight shifts in their peaks. Our results can be used to develop promising materials for many applications, such as biological sensors, and optoelectronic devices.

Original language	English (US)
Pages (from-to)	114602
Journal	Physica E: Low-Dimensional Systems and Nanostructures
Volume	128
DOIs	https://doi.org/10.1016/j.physe.2020.114602
State	Published - Jan 6 2021
Externally published	Yes

Bibliographical note

KAUST Repository Item: Exported on 2022-06-14
Acknowledgements: The authors would like to acknowledge the use of the computing resources through the computational Cy-Tera Project (NEA YΠOΔOMH/ΣTPATH/0308/31), which is co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research Promotion Foundation. We would like to acknowledge the support of the supercomputing facility at the Bibliotheca Alexandrina, Alexandria, Egypt. A. Maarouf would like to acknowledge the use of the resources of the Supercomputing Laboratory at KAUST, Thuwal, KSA.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.

ASJC Scopus subject areas

Atomic and Molecular Physics, and Optics
Electronic, Optical and Magnetic Materials
Condensed Matter Physics

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10.1016/j.physe.2020.114602

Cite this

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title = "Pristine and holey graphene quantum dots: Optical properties using time independent and dependent density functional theory",

abstract = "The zero bandgap of graphene limits its utilization in optoelectronics. Quantum confinement in finite-size graphene structures, such as graphene quantum dots (GQDs) and holey GQDs, may offer a path for generating a wide range of HOMO-LUMO gaps. Edge terminations and pore passivations in these structures provide further means to alter their optical properties. In this work, we study the structural stabilities and optical properties of GQDs and holey GQDs with different sizes, edge terminations, and pore passivations, using density functional theory (DFT) as well as time dependent DFT. We find that the optical spectra of GQDs depend primarily on their size. Edge termination has a small influence on the spectra; shifting the absorption peaks by ~ 0.2 eV, which gets smaller for larger GQDs. Creation of pores in GQDs lead to the emergence of new peaks in their absorption spectra. Pore passivation seems to have the biggest effect on the absorption spectra of holey GQDs, while their termination leads to slight shifts in their peaks. Our results can be used to develop promising materials for many applications, such as biological sensors, and optoelectronic devices.",

author = "Abdelati, {Mohamed A.} and Fadlallah, {Mohamed M.} and Gamal, {Yosr E.E.D.} and Maarouf, {Ahmed A.}",

note = "KAUST Repository Item: Exported on 2022-06-14 Acknowledgements: The authors would like to acknowledge the use of the computing resources through the computational Cy-Tera Project (NEA YΠOΔOMH/ΣTPATH/0308/31), which is co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research Promotion Foundation. We would like to acknowledge the support of the supercomputing facility at the Bibliotheca Alexandrina, Alexandria, Egypt. A. Maarouf would like to acknowledge the use of the resources of the Supercomputing Laboratory at KAUST, Thuwal, KSA. This publication acknowledges KAUST support, but has no KAUST affiliated authors.",

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AU - Fadlallah, Mohamed M.

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AU - Maarouf, Ahmed A.

N1 - KAUST Repository Item: Exported on 2022-06-14 Acknowledgements: The authors would like to acknowledge the use of the computing resources through the computational Cy-Tera Project (NEA YΠOΔOMH/ΣTPATH/0308/31), which is co-funded by the European Regional Development Fund and the Republic of Cyprus through the Research Promotion Foundation. We would like to acknowledge the support of the supercomputing facility at the Bibliotheca Alexandrina, Alexandria, Egypt. A. Maarouf would like to acknowledge the use of the resources of the Supercomputing Laboratory at KAUST, Thuwal, KSA. This publication acknowledges KAUST support, but has no KAUST affiliated authors.

PY - 2021/1/6

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N2 - The zero bandgap of graphene limits its utilization in optoelectronics. Quantum confinement in finite-size graphene structures, such as graphene quantum dots (GQDs) and holey GQDs, may offer a path for generating a wide range of HOMO-LUMO gaps. Edge terminations and pore passivations in these structures provide further means to alter their optical properties. In this work, we study the structural stabilities and optical properties of GQDs and holey GQDs with different sizes, edge terminations, and pore passivations, using density functional theory (DFT) as well as time dependent DFT. We find that the optical spectra of GQDs depend primarily on their size. Edge termination has a small influence on the spectra; shifting the absorption peaks by ~ 0.2 eV, which gets smaller for larger GQDs. Creation of pores in GQDs lead to the emergence of new peaks in their absorption spectra. Pore passivation seems to have the biggest effect on the absorption spectra of holey GQDs, while their termination leads to slight shifts in their peaks. Our results can be used to develop promising materials for many applications, such as biological sensors, and optoelectronic devices.

AB - The zero bandgap of graphene limits its utilization in optoelectronics. Quantum confinement in finite-size graphene structures, such as graphene quantum dots (GQDs) and holey GQDs, may offer a path for generating a wide range of HOMO-LUMO gaps. Edge terminations and pore passivations in these structures provide further means to alter their optical properties. In this work, we study the structural stabilities and optical properties of GQDs and holey GQDs with different sizes, edge terminations, and pore passivations, using density functional theory (DFT) as well as time dependent DFT. We find that the optical spectra of GQDs depend primarily on their size. Edge termination has a small influence on the spectra; shifting the absorption peaks by ~ 0.2 eV, which gets smaller for larger GQDs. Creation of pores in GQDs lead to the emergence of new peaks in their absorption spectra. Pore passivation seems to have the biggest effect on the absorption spectra of holey GQDs, while their termination leads to slight shifts in their peaks. Our results can be used to develop promising materials for many applications, such as biological sensors, and optoelectronic devices.

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JO - Physica E: Low-Dimensional Systems and Nanostructures

JF - Physica E: Low-Dimensional Systems and Nanostructures

ER -

Pristine and holey graphene quantum dots: Optical properties using time independent and dependent density functional theory

Abstract

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