Doped Graphene Quantum Dots UV-vis Absorption Spectrum: A High-Throughput TDDFT Study.

Area of Science:

• Computational Materials Science
• Quantum Chemistry
• Nanotechnology

Background:

• Graphene quantum dots (GQDs) exhibit tunable optical properties.
• Understanding the influence of doping and size on GQD spectra is crucial for applications.
• Predictive modeling can guide experimental synthesis of GQDs with desired characteristics.

Purpose of the Study:

• To computationally investigate the excited states and UV-vis absorption spectra of doped graphene quantum dots.
• To analyze the systematic trends in absorption spectra based on GQD size, dopant type, and dopant concentration.
• To provide a framework for designing GQD mixtures with tailored absorption profiles.

Main Methods:

• Time-dependent density functional theory (TD-DFT) calculations were employed.
• Calculations were performed for 63 square-shaped graphene quantum dots.
• Doping was systematically varied using B, N, O, S, and P at 1.5%, 3%, 5%, and 7% concentrations.

Main Results:

• UV-vis absorption spectra were calculated, revealing distinct spectral features.
• Trends in spectral peaks (UV and visible regions) and overall absorption were mapped against size, dopant type, and percentage.
• The study demonstrates how spectral profiles evolve within the explored chemical parameter space.

Conclusions:

• Doping type, concentration, and GQD size significantly influence UV-vis absorption spectra.
• The findings enable the rational design of GQD mixtures for specific optical absorption targets.
• This computational approach facilitates the development of advanced materials for optoelectronic applications.