Penta-C20: A Superhard Direct Band Gap Carbon Allotrope Composed of Carbon Pentagon

Materials

Qingyang Fan¹  Wei Zhang²  Changchun Chai²  Yanxing Song²  Yintang Yang² 

[1] College of Information and Control Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China;Key Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi’an 710071, China;

关键词: carbon allotrope;    superhard materials;    direct band gap;    mechanical property;    stability;   

DOI  :  10.3390/ma13081926

来源: DOAJ

【 摘 要 】

A metastable sp³-bonded carbon allotrope, Penta-C₂₀, consisting entirely of carbon pentagons linked through bridge-like bonds, was proposed and studied in this work for the first time. Its structure, stability, and electronic and mechanical properties were investigated based on first-principles calculations. Penta-C₂₀ is thermodynamically and mechanically stable, with equilibrium total energy of 0.718 and 0.184 eV/atom lower than those of the synthesized T-carbon and supercubane, respectively. Penta-C₂₀ can also maintain dynamic stability under a high pressure of 100 GPa. Ab initio molecular dynamics (AIMD) simulations indicates that this new carbon allotrope can maintain thermal stability at 800 K. Its Young’s modulus exhibits mechanical anisotropy. The calculated ideal tensile and shear strengths confirmed that Penta-C₂₀ is a superhard material with a promising application prospect. Furthermore, Penta-C₂₀ is a direct band gap carbon based semiconducting material with band gap of 2.89 eV.

【 授权许可】

Unknown