Multifunctional Binary Monolayers GexPy: Tunable Band Gap, Ferromagnetism, and Photocatalyst for Water Splitting

Pengfei Li, Wei Zhang, Dongdong Li, Changhao Liang, Xiao Cheng Zeng

Research output: Contribution to journalArticle

16 Scopus citations

Abstract

The most stable structures of two-dimensional GexPy and GexAsy monolayers with different stoichiometries (e.g., GeP, GeP2, and GeP3) are explored systematically through the combination of the particle-swarm optimization technique and density functional theory optimization. For GeP3, we show that the newly predicted most stable C2/m structure is 0.16 eV/atom lower in energy than the state-of-the-art P3 m1 structure reported previously (Nano Lett. 2017, 17, 1833). The computed electronic band structures suggest that all the stable and metastable monolayers of GexPy are semiconductors with highly tunable band gaps under the biaxial strain, allowing strain engineering of their band gaps within nearly the whole visible-light range. More interestingly, the hole doping can convert the C2/m GeP3 monolayer from nonmagnetic to ferromagnetic because of its unique valence band structure. For the GeP2 monolayer, the predicted most stable Pmc21 structure is a (quasi) direct-gap semiconductor that possesses a high electron mobility of ∼800 cm2 V-1 s-1 along the ka direction, which is much higher than that of MoS2 (∼200 cm2 V-1 s-1). More importantly, the Pmc21 GeP2 monolayer not only can serve as an n-type channel material in field-effect transistors but also can be an effective catalyst for splitting water.

Original languageEnglish (US)
Pages (from-to)19897-19905
Number of pages9
JournalACS Applied Materials and Interfaces
Volume10
Issue number23
DOIs
StatePublished - Jun 13 2018

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Keywords

  • band structure
  • ferromagnetism
  • semiconductor
  • two-dimensional
  • water splitting

ASJC Scopus subject areas

  • Materials Science(all)

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