# Investigating the Absorption Properties of Pure and Nitrogen-Doped Carbon Clusters as Models for the Core of Carbon Nanodots

## TL;DR

This study uses computational models to explore how nitrogen doping affects the optical properties of carbon nanodot cores.

## Contribution

A bottom-up computational approach is introduced to model nitrogen-doped carbon clusters as CND core analogs.

## Key findings

- Nitrogen substitution alters the electronic and optical properties of carbon clusters.
- Computed UV/vis spectra help explain property changes in doped carbon nanodot models.

## Abstract

The study of amorphous carbon structures of different
sizes and
extensions is relevant to many research areas, including electrode
processes (e.g., intercalation), astrochemistry, catalysis, and sensors.
While the structure of amorphous carbon structures has been investigated
thoroughly in the past, a systematic analysis of their properties
upon doping with functional groups is far less extensive. This aspect
is particularly important for carbon nanodots (CNDs), a photoluminescent
species of carbon-based nanoparticles whose optical properties arise
from the interplay between core electronic structure, surface states,
heteroatom doping, and molecular fluorophores. Despite extensive experimental
work, an atomistic rationalization of their optical properties is
still not available. In this study, we adopt a bottom-up computational
approach using amorphous pure carbon clusters (C10–C60) and nitrogen-substituted ones (C9N–C59N) as models for the unsaturated and partially doped domains
of CND cores. Structural isomers were generated along with computed
UV/vis spectra to rationalize the property changes upon nitrogen substitution.