New group V graphyne

two-dimensional direct semiconductors with remarkable carrier mobilities, thermoelectric performance, and thermal stability

verfasst von
Y. Wu, C. Ma, Y. Chen, B. Mortazavi, Z. Lu, X. Zhang, K. Xu, H. Zhang, W. Liu, T. Rabczuk, H. Zhu, Z. Fang, R. Zhang
Abstract

The past decades have witnessed the great progress and successes in the research and applications of two-dimensional (2D) carbon materials such as graphene, graphdiyne, and so on. Similar to pure 2D carbon materials, 2D carbon nitride–like h-BN also possesses excellent electronic, mechanical, and optical properties. In this work, stimulated by the chemical tuition of atomic substitution, a new family of monolayer group V graphyne (C16N4, C16P4, and C16As4) with rhombic lattice is designed by replacing some C atoms with group V elements of N, P, or As in 2D graphyne. By using first-principles approach, we investigated their thermal stability, electronic/thermal transport properties, and thermoelectric performance and found that N(P,As)-graphyne monolayers are semiconductors with considerable direct bandgap values of 0.87 eV (0.59 eV, 0.71 eV), respectively. The ab initio molecular dynamics results demonstrate that N(P,As)-graphyne monolayers remain stable up to 1500 K. They all possess high carrier mobilities with the order of 105cm2V−1s−1 for electrons along the zigzag direction. Under the uniaxial tensile strains in the range of 0% to 10%, N(P,As)-graphyne monolayers keep direct-bandgap properties, and the effective mass of carriers can be efficiently tuned. Moreover, the calculated thermoelectric figure of merits at room temperature for the new monolayer group V graphyne are 0.62∼0.69 owing to the low lattice thermal conductivity, which are comparable with some conventional thermoelectric materials. Their excellent electronic transport and thermoelectric performance make N(P,As)-graphyne monolayers promising in high-speed (opto)electronic and thermoelectric devices, and the strain-engineering properties may lead to applications in flexible nanoelectronics.

Organisationseinheit(en)
PhoenixD: Simulation, Fabrikation und Anwendung optischer Systeme
Externe Organisation(en)
Fudan University
Nanjing University
Bauhaus-Universität Weimar
Typ
Artikel
Journal
Materials Today Physics
Band
12
Publikationsdatum
03.2020
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Werkstoffwissenschaften (insg.), Energie (sonstige), Physik und Astronomie (sonstige)
Elektronische Version(en)
https://doi.org/10.1016/j.mtphys.2019.100164 (Zugang: Geschlossen)