Density Functional Theory Calculations Revealing Metal-like Band Structures and Work Function Variation for Ultrathin Gallium Arsenide (111) Surface Layers

Chih Shan Tan*, Michael H. Huang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

Density functional theory (DFT) calculations have been performed on tunable numbers of gallium arsenide (100), (110), and (111) planes for their electron density of states (DOS) plots and the corresponding band diagrams. The GaAs (100) and (110) planes show the same semiconducting band structure with tunable plane layers and a band gap of 1.35 eV around the Fermi level. In contrast, metal-like band structures are obtained with a continuous band structure around the Fermi level for 1, 2, 4, 5, 7, and 8 layers of GaAs (111) planes. For 3, 6, and 9 GaAs (111) planes, the same semiconducting band structure as seen in the (100) and (110) planes returns. The results suggest the GaAs {111} face should be more electrically conductive than its {100} and {110} faces, due to the merged conduction band and valence band. GaAs (100) and (110) planes give a fixed work function, but the (111) planes have variable work function values that are smaller than that obtained for the (100) and (110) planes. Furthermore, bond length, bond geometry, and frontier orbital electron number and energy distribution show notable differences between the metal-like and semiconducting plane cases, so the emergence of plane-dependent electronic properties have quantum mechanical origin at the orbital level. GaAs should possess similar facet-dependent electronic properties to those of Si and Ge.

Original languageEnglish
Pages (from-to)2316-2321
Number of pages6
JournalChemistry - An Asian Journal
Volume14
Issue number13
DOIs
StatePublished - 1 Jul 2019

Keywords

  • density functional theory calculations
  • density of states
  • facet-dependent properties
  • gallium arsenide
  • semiconductors

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