Pronounced excitonic effects in two-dimensional fullerene-based monolayer materials

Area of Science:

• Materials Science
• Condensed Matter Physics
• Quantum Chemistry

Background:

• Two-dimensional (2D) fullerene materials possess unique properties, particularly pronounced excitonic effects.
• These properties suggest significant potential for applications in optoelectronics.

Purpose of the Study:

• To comprehensively investigate the quasiparticle (QP) and excitonic properties of the C20-2D monolayer.
• To explore the impact of magnesium (Mg) embedding on these properties and optical absorption.

Main Methods:

• Density Functional Theory (DFT) for electronic structure calculations.
• Many-Body Perturbation Theory (MBPT) using the GW approximation.
• Bethe-Salpeter Equation (GW-BSE) for excitonic property calculations.

Main Results:

• The C20-2D monolayer exhibits significant excitonic effects with an exciton binding energy of 1.58 eV.
• Embedding Mg induces polarization and enhances dielectric screening in the C20-2D monolayer.
• Mg embedding shifts excitons from Frenkel to Wannier type, altering optical absorption intensity and range.

Conclusions:

• The C20-2D fullerene monolayer displays strong excitonic properties suitable for optoelectronics.
• Embedding Mg offers a method to tune the electronic and optical characteristics of fullerene materials.
• These findings provide insights for designing next-generation optoelectronic devices based on tunable fullerene systems.