Quadrene: A Novel Quasi-2D Carbon Allotrope with High Carrier Mobility

TL;DR

Quadrene is a newly discovered quasi-2D carbon allotrope with a stable, anisotropic structure exhibiting high carrier mobility and promising applications in nanoelectronics and optoelectronics.

Contribution

This work introduces Quadrene, a novel carbon allotrope with unique quasi-2D structure, high stability, and exceptional electronic and mechanical properties validated by first-principles calculations.

Findings

High intrinsic stability with negative formation energy

Exceptional carrier mobilities up to 6.40 x 10^6 cm^2/V·s

Anisotropic mechanical and electronic properties

Abstract

We present a comprehensive first-principles investigation of a novel carbon allotrope characterized by quasi-tetragonal atomic motifs and quasi-two-dimensional structural behavior. Structural analysis reveals an open framework composed of alternating diamond-like and square units, while thermodynamic assessments indicate a negative formation energy, suggesting high intrinsic stability. Phonon spectra confirm dynamical robustness, and \textit{ab initio} molecular dynamics simulations at 1000~K validate its thermal resilience. Furthermore, the system exhibits an indirect bandgap of 1.58 eV at the HSE06 level, anisotropic mechanical behavior, and a broadband optical response, reinforcing its potential for nanoelectronic and optoelectronic applications. The highly anisotropic mechanical behavior is characterized by an in-plane Young's modulus ranging from 80 to 550 GPa, depending on crystallographic direction. Additionally, the electronic transport properties exhibit pronounced anisotropy, with hole mobilities reaching up to 5.83 x 10^6 cm^2/V . s and electron mobilities up to 6.40 x 10^6 cm^2/V . s along different crystallographic directions, highlighting the material's potential for directionally selective nanoelectronic device applications.