Eur. Phys. J. Plus (2022) 137: 233
https://doi.org/10.1140/epjp/s13360-022-02418-y

Regular Article

Optimized nonlinear optical (NLO) response of silicon carbide nanosheet by alkali metals doping: a DFT insight

¹ Department of Chemistry, COMSATS University Islamabad, Lahore Campus, 54600, Lahore, Pakistan
² Department of Chemistry, COMSATS University, 22060, Abbottabad Campus, Abbottabad, Pakistan
³ Department of Chemistry, College of Science, University of Bahrain, P.O. Box 32038, Sakhir, Bahrain
⁴ Interdisciplinary Research Centre in Biomedical Materials (IRCBM), COMSATS University Islamabad, Lahore Campus, 54600, Lahore, Pakistan
⁵ Department of Chemistry, School of Computer, Mathematical and Natural Sciences, Morgan State University, 21251, Baltimore, MD, USA
⁶ School of Chemical Engineering, and Inner Mongolia Key Laboratory of Theoretical and Computational Chemistry Simulation, Inner Mongolia University of Technology, 010051, Hohhot, People’s Republic of China
⁷ School of Energy and Power Engineering, Inner Mongolia University of Technology, 010051, Hohhot, People’s Republic of China

^h mazhargilani@cuilahore.edu.pk

Received: 9 August 2021
Accepted: 25 January 2022
Published online: 16 February 2022

Abstract

Alkali metal (M = Li, Na, K)-doped silicon carbide nanosheets (M@SiCNs) have been theoretically investigated to evaluate their geometries, stabilities and nonlinear optical responses through density functional theory. Computationally determined interaction energies confirm the stability of newly designed M@SiCNs materials. The nature of the interactions between alkali metals and SiCNs is explored by non-covalent interaction (NCI) analysis. The doping of alkali metals on silicon carbide nanosheet has led to a maximum of 62% reduction in the E_(H–L) gap. The isomer K@SiCNs-III has a maximum hyperpolarizability (β_o) of 7.7 × 10⁴ au in comparison with that of undoped SiCNs. The frequency-dependent SHG and EOPE are also determined. The value of 4.47 × 10⁸ au is observed for ESHG, while for induced dc-Kerr effect the value is 3.96 × 10⁹ au. Furthermore, these structures have a high nonlinear quadratic refractive index of 1.32 × 10^–14 au. The significant NPA charges, low ionization potential values, higher chemical softness values, low excitation energies and DOS spectra justify the heightened NLO response. The TD-DFT study shows that these complexes have λ_max in the visible and near-IR regions. This work may provide valuable guidelines for designing new silicon carbide-based materials with enhanced NLO response.