Structural Stability, Electronic, Magnetic and Optical Properties of Rectangular Graphene and Boron-Nitride Quantum Dots: Effects of Size, Substitution and Electric Field

TL;DR

This study uses density functional theory to explore how size, substitution, and electric fields influence the stability, electronic, magnetic, and optical properties of rectangular graphene, boron-nitride, and hybrid quantum dots, revealing tunable features for device applications.

Contribution

It introduces a comprehensive analysis of how substitution and external electric fields can tailor properties of graphene and BN quantum dots, advancing their potential in opto-electronic and spintronic devices.

Findings

Substitution enables broad NIR absorption (~2000 nm).

Spin-polarized HOMO-LUMO gaps achieved without external bias.

Properties can be tuned by changing substitution position and amount.

Abstract

Using density functional theory calculations, we have examined the structural stability, electronic, magnetic and optical properties of rectangular shaped quantum dots (QDs) of graphene (G), Boron Nitride (BN) and their hybrids. Different hybrid QDs have been considered by substituting a GQD (BNQD) with BN-pairs (carbon atoms) at different positions. Several parameters like size, amount of substitution etc. have been varied for all these QDs (GQDs, BNQDs, hybrid-QDs) to monitor the corresponding changes in their properties. Among the considered parameters, we find that substitution can act as a powerful tool to attain interesting properties with these QDs, for example, broad range of absorption (~2000 nm) in the near infrared (NIR) region, spin-polarized HOMO-LUMO gaps without the application of any external-bias etc., which are highly required in the preparation of opto-electronic, electronic/spintronic devices etc. Explanations have been given in details by varying different factors, like, changing the position and amount of substitution, application of external electric-field etc., to ensure the reliability of our results.