Doped Graphene Quantum Dots UV-Vis Absorption Spectrum: A high-throughput TDDFT study

TL;DR

This study uses high-throughput TDDFT calculations to analyze how doping and size affect the UV-Vis absorption spectra of graphene quantum dots, providing insights for designing specific optical properties.

Contribution

It presents a systematic high-throughput TDDFT analysis of doped GQDs, revealing trends in their absorption spectra based on size, dopant type, and concentration.

Findings

Absorption peaks vary systematically with size and doping.

Doping influences the spectral shape and peak positions.

Spectra can be tailored for specific optical applications.

Abstract

We report on time-dependent density functional theory (TDDFT) calculations of the excited states of 63 different graphene quantum dots (GQDs) in square shape with side lengths 1 nm, 1.5 nm and 2 nm. We investigate the systematics and trends in the UV-Vis absorption spectra of these GQDs, which are doped with elements B, N, O, S and P at dopant percentages 1.5%, 3%, 5% and 7%. The results show how the peaks in the UV and visible parts of the spectrum as well as the total absorption evolve in the chemical parameter space along the coordinates of size, dopant type and dopant percentage. The absorption spectra calculated here can be used to obtain particular GQD mixture proportions that would yield a desired absorption profile such as flat absorption across the whole visible spectrum or one that is locally peaked around a chosen wavelength.