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

摘要

Using density functional theory calculations, we have examined the structuralstability, electronic, magnetic and optical properties of rectangular shapedquantum dots (QDs) of graphene (G), Boron Nitride (BN) and their hybrids.Different hybrid QDs have been considered by substituting a GQD (BNQD) withBN-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 theconsidered parameters, we find that substitution can act as a powerful tool toattain interesting properties with these QDs, for example, broad range ofabsorption (~2000 nm) in the near infrared (NIR) region, spin-polarizedHOMO-LUMO gaps without the application of any external-bias etc., which arehighly required in the preparation of opto-electronic, electronic/spintronicdevices etc. Explanations have been given in details by varying differentfactors, like, changing the position and amount of substitution, application ofexternal electric-field etc., to ensure the reliability of our results.