Band Modulation for Silicene and Graphene Quantum Dots: A First-Principles Calculation

TL;DR

This paper uses first-principles calculations to explore how the size and shape of silicene and graphene quantum dots influence their electronic and magnetic properties, revealing tunable energy gaps and magnetic behaviors.

Contribution

It provides a detailed analysis of the effects of quantum dot shape and size on electronic and magnetic properties using first-principles methods, including embedded quantum dots.

Findings

Energy gap decreases with increasing dot size.

Shape determines magnetic properties: triangular (magnetic semiconductor), parallelogram (antiferromagnetic), hexagonal (non-magnetic).

Size and shape control can tune electronic and magnetic behaviors.

Abstract

The band modulation of the silicene and graphene quantum dots is investigated by a first-principles method. This study includes the ordinary silicene and graphene quantum dots and the embedded quantum dots in the hydrogenated silicene and graphene. The shapes and sizes of quantum dots are recognized as important factors for the electronic properties. We studied several types of quantum dots: triangular, parallelogram, rectangular, hexagonal dots. It demonstrates the energy gap of the quantum dot can be tuned by the dot size, the larger of the dot the smaller the energy gap. Moreover, the shapes affect the magnetism of the quantum dots. The triangular dot exhibits as magnetic semiconductor; the parallelogram dot shows antiferromagnetic characteristics; while the hexagonal dot is non-magnetic. Control the size and shape of a silicene or graphene quantum dot can manipulate its magnetism and electronic properties.