The electronic properties of phosphorus-doped GaN nanowires from first-principle calculations

• Published in: Journal of alloys and compounds Vol. 596; pp. 92 - 97
• Main Authors: Fu, Nannan, Li, Enling, Cui, Zhen, Ma, Deming, Wang, Wei, Zhang, Yulong, Song, Sha, Lin, Jie
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 25.05.2014; Elsevier
• Subjects: Atomic properties; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron and ion emission by liquids and solids; impact phenomena; Electronic properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic structure of nanoscale materials : clusters, nanoparticles, nanotubes, and nanocrystals; Exact sciences and technology; Field emission, ionization, evaporation, and desorption; First principles; Gallium base alloys; Gallium nitrides; Impurities; Mathematical analysis; Nanowires; Nitrides; P-doped GaN nanowires; Physics; P-doped GaN nanowires; Electronic properties; First principles; Pseudopotential methods; Phosphorus additions; Lattice parameters; Gallium nitride; Electron field emission; Covalent bonds; Electronic structure; Density functional method; Donor center; Nanowires; Impurity states; Ionic bonds
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2014.01.186

[Display omitted] •The P impurities tend to enrich at the surface of GaN nanowires.•The lattice parameters of GaN nanowires are changed by the P impurity.•Donor impurity level appears when the P impurity substitutes for the Ga atom.•The band gap decreases slightly when the P impurity substitutes for the N atom. The electronic properties of phosphorus-doped unsaturated and saturated gallium nitride (GaN) nanowires have been investigated from first-principles using the ultrasoft pseudopotential method. The results of these calculations indicate that the P impurities are enriched at the surface of gallium nitride nanowires, and that the structural symmetry of GaN nanowires is broken due to changes in the lattice parameters. When the P impurity substitutes for the Ga atom, the width of band gap increases at the Γ point, a donor impurity level appears in the band gap, and the P impurity and adjacent N atoms exists covalent interaction. Moreover, when the P impurity substitutes for the N atom, the width of the band gap decreases slightly at the Γ point, there is no obvious impurity level in the band gap, and P–Ga covalent bonds are formed, including those composed of ionic bonds. These conclusions indicate that the incorporation of P impurities can improve the field emission performance of GaN nanowires, which is consistent with the experimental results.