A DFT Investigation of the Electronic and Optical Properties of Pentadiamond

TL;DR

This study uses first-principles DFT calculations to explore the electronic and optical properties of the newly proposed 3D carbon allotrope, pentadiamond, revealing its potential for UV optical applications.

Contribution

It provides the first detailed theoretical analysis of pentadiamond's electronic structure and optical behavior, highlighting its unique properties among carbon allotropes.

Findings

Pentadiamond is an indirect bandgap semiconductor with a 2.50 eV gap (GGA-PBE) and 3.31 eV (HSE06).

It exhibits low reflectivity (~40%) across the optical spectrum, suitable for UV collection.

Displays optical activity in the UV range, unlike other carbon allotropes.

Abstract

Recently, a new carbon 3D carbon allotrope named pentadiamond was proposed. Pentadiamond is composed of carbon atoms in mixed sp$^2$ and sp$^3$-like hybridization. In this work, we have carried out a detailed investigation of the electronic and optical properties of pentadiamond structure using first-principles (DFT) methods. Our results show that pentadiamond has an indirect bandgap semiconductor of $2.50$ eV with GGA-PBE and $3.31$ eV with HSE06. Its static dielectric constant is $4.70$ and the static refractive index is $2.16$. Pentadiamond presents low reflectivity, almost 40$\%$, for all-optical spectrum, making it a good structure to be used as a UV collector. Also, pentadiamond exhibits optical activity in the UV range where other carbon allotropes, such as diamond and 8-tetra(2,2) tubulane show no activity.