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Change in nonlinear optical response of C24 nanocage upon doping with lithium based superalkalis

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Naveen Kosar at University of Management and Technology
Naveen Kosar
Ayesha Safdar
Ayesha Safdar
Ayesha Safdar
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Muhamad Imran at Shenzhen University
Muhamad Imran
Adnan Younis
Adnan Younis
Adnan Younis
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Abstract and Figures

Density functional theory (DFT) calculations are used to analyze the change in nonlinear optical (NLO) response, electronic and geometric properties of the Li based superalkalis doped C24 nanocage. It was observed that the adsorption of Li4N, Li3O and Li2F superalkalis on C24 nanocage results in thermodynamically stable isomers (A-F). The energy gap between the highest occupied and the lowest unoccupied molecular orbitals (GH-L) is reduced after superalkalis doping on carbon (C24) nanocage. Density of states spectra depict the strong contribution of superalkalis in HOMOs of the considered complexes. Natural bond orbital (NBO) charge analysis showed that the charge is being transferred from superalkali toward C24 nanocage. The values of polarizability (α o ) and hyperpolarizability (β o ) showed that doping of superalkalis on C24 has a significant effect on its NLO response, resulting in a considerable increase in values of α o and β o . Li4N@C24 isomer E showed the highest β o value of 6470.74 au. Time dependent density functional theory (TD-DFT) calculations are implemented to analyze the absorption spectra. This research provides unique and highly efficient superalkalis doped C24 isomers for their applications in future electronic devices.
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Phys. Scr. 99 (2024)085123 https://doi.org/10.1088/1402-4896/ad6354
PAPER
Change in nonlinear optical response of C
24
nanocage upon doping
with lithium based superalkalis
Naveen Kosar
1,∗
, Ayesha Safdar
1,∗
, Muhammad Imran
2
, Adnan Younis
3
and Tariq Mahmood
4,5,∗
1
Department of Chemistry, University of Management and Technology (UMT), C-11, Johar Town Lahore, Pakistan
2
Research Center for Advanced Materials Science (RCAMS), Department of Chemistry, Faculty of Science, King Khalid University,
PO Box 9004, Abha 61413, Saudi Arabia
3
Department of Physics, College of Science, United Arab Emirates University, Al-Ain 15551, United Arab Emirates
4
Department of Chemistry, COMSATS University Islamabad, Abbottabad Campus, Abbottabad, KPK, 22060, Pakistan
5
Department of Chemistry, College of Science, University of Bahrain, Sakhir PO Box 32038, Bahrain
∗
Authors to whom any correspondence should be addressed.
E-mail: naveen.kosar@umt.edu.pk,ayounis@uaeu.ac.a.e and mahmood@cuiatd.edu.pk
Keywords: nonlinear optical, hyperpolarizability, superalkali, DFT, C
24
Supplementary material for this article is available online
Abstract
Density functional theory (DFT)calculations are used to analyze the change in nonlinear optical
(NLO)response, electronic and geometric properties of the Li based superalkalis doped C
24
nanocage.
It was observed that the adsorption of Li
4
N, Li
3
O and Li
2
F superalkalis on C
24
nanocage results in
thermodynamically stable isomers (A-F). The energy gap between the highest occupied and the lowest
unoccupied molecular orbitals (G
H-L
)is reduced after superalkalis doping on carbon (C
24
)nanocage.
Density of states spectra depict the strong contribution of superalkalis in HOMOs of the considered
complexes. Natural bond orbital (NBO)charge analysis showed that the charge is being transferred
from superalkali toward C
24
nanocage. The values of polarizability (α
o
)and hyperpolarizability (β
o
)
showed that doping of superalkalis on C
24
has a significant effect on its NLO response, resulting in a
considerable increase in values of α
o
and β
o
.Li
4
N@C
24
isomer Eshowed the highest β
o
value of
6470.74 au. Time dependent density functional theory (TD-DFT)calculations are implemented to
analyze the absorption spectra. This research provides unique and highly efficient superalkalis doped
C
24
isomers for their applications in future electronic devices.
1. Introduction
Molecules or clusters having ionization energy lower than cesium (Cs)and possess excellent reducing properties
are known as superalkalis [1]. Superalkalis can serve as hydrogen storage materials [2]and noble-gas-trapping
agents [3]. Their unique structure, strong reducing properties have made those interesting species. Due to low
ionization potential superalkalis have ability to enhance NLO response of materials by donating excess
electrons [4].
Since last few years, many reports have been published regarding the synthesis and designing of NLO
materials [5–12]. NLO is a field of optics that defines the behavior of light in a medium, in which the polarization
density behaves non-linearly toward electric field of coming light [13]. NLO Materials are widely used in signal
processing [14], optical information [15], electronic devices [16], photosensitive communication [17],
molecular scale memory devices [18], energy storage devices [19]and data storage [20]. These also possess wide
rang medical applications [21], including biosensors [22], endoscopy [23], and optical surgery [24]. An ideal
NLO material should have small dielectric constant, high hyperpolarizability value and low cost, fast detection
time, deep UV permeability, and low permittivity. Over the last two decades, scientists have used different
strategies to study the NLO response of different organic [25]and inorganic materials [26]. These strategies
include: excess electron system by doping, metal–ligand framework, electron push–pull mechanism, and
RECEIVED
21 March 2024
REVISED
27 June 2024
ACCEPTED FOR PUBLICATION
15 July 2024
PUBLISHED
25 July 2024
© 2024 IOP Publishing Ltd
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