Engineering the De-localized States of Graphene Quantum Dots

TL;DR

This paper predicts that by combining many-body and first-principles methods, doped graphene quantum dots can exhibit high oscillator strength and tunable states suitable for photonic and photovoltaic applications.

Contribution

It introduces a novel approach to engineer de-localized states in graphene quantum dots using a combination of extended Hubbard model and first-principles calculations.

Findings

High oscillator strength near-IR states due to Davydov splitting

Strain promotes closely spaced bright states for coherent excitation

Dark states can be tuned for photovoltaic applications

Abstract

Employing a combination of many-body configuration interaction method described by extended Hubbard model along with first principle calculations we predict the emergence of high oscillator strength at near-IR region which originates from the Davydov type of splitting in doped graphene quantum dots (GQD). Incorporation of strain in GQD promotes closely spaced bright states inciting for coherent excitation. Controlling the destructive interference of the functionalized nano graphene quantum states, the dark states can be tuned towards red end ensuing the system as a good candidate for photocell whereas coherent states can be tailored to concentrate the light at very high intensity resulting an opportunity for photonic device