Adatom kinetics on nonpolar InN surfaces: Implications for one-dimensional nanostructures growth

Abstract

The adatom kinetics processes of adsorption and diffusion for In and N species on nonpolar InN a- and m-planes have been studied using ab initio density functional theory calculations. Our results reveal remarkable in-plane anisotropic potential energy surfaces, consistently with experimental data on vertically c-oriented one-dimensional nanostructure formation; we demonstrate that lateral wall morphology strongly determinates the contribution of diffusion to the growth process.

Correlation of Morphology Evolution with Carrier Dynamics in InN Films Heteroepitaxially Grown by MOMBE

“…The pronounced 2D growth mode is related to the breakdown of anisotropic-directed growth at higher growth temperatures, and increased surface atomic mobility may cause more indium atoms to spread to the (0001) surface, providing more stable binding sites. At the lower temperature of 470 • C, the InN nanorods (NRs) with nonpolar m-plane side facets grow spontaneously along the c-direction, due to the lower diffusion barrier of In adatoms along the m-plane than along the c-plane, as reported by Aliano et al [25], which results in a higher sticking coefficient of In atoms on the c-plane than that on the m-plane. Thus, In adatoms have a low sticking coefficient on the m-plane InN NR sidewalls and nucleate on the c-terraces, promoting the 1D growth of dislocationfree InN NR and reaching a length of 1 µm at a density of about 10 9 cm −2 [25,26].…”

“…At the lower temperature of 470 • C, the InN nanorods (NRs) with nonpolar m-plane side facets grow spontaneously along the c-direction, due to the lower diffusion barrier of In adatoms along the m-plane than along the c-plane, as reported by Aliano et al [25], which results in a higher sticking coefficient of In atoms on the c-plane than that on the m-plane. Thus, In adatoms have a low sticking coefficient on the m-plane InN NR sidewalls and nucleate on the c-terraces, promoting the 1D growth of dislocationfree InN NR and reaching a length of 1 µm at a density of about 10 9 cm −2 [25,26]. A higher growth temperature of InN is expected to bring about a higher decomposition rate because of thermal decomposition of the grown InN.…”

“…According to earlier literature, the growth conditions of the N-rich regime can inhibit the formation of indium droplets; if no indium droplets appear, we may hypothesize that InN nanorods were grown through a no-catalytic-growth mechanism. Although no metal particles were observed at the top, we could not completely rule out the possibility of a VLS-like or self-catalyzed mechanism, as In atoms could desorb at high temperatures [24][25][26][27]. The pronounced 2D growth mode is related to the breakdown of anisotropic-directed growth at higher growth temperatures, and increased surface atomic mobility may cause more indium atoms to spread to the (0001) surface, providing more stable binding sites.…”

Review—Extremely Thin Amorphous Indium Oxide Transistors

“…A variety of experimental [ 27,38 ] and theoretical [ 39–41 ] results demonstrate that the electronic properties of indium oxide are robust against disorder. For example, detailed molecular dynamics and density functional theory (DFT) calculations predict negligible changes to the character of the conduction band with increasing amorphization, [ 39 ] for example, a <5% change in electron effective mass.…”

A New Theoretical Insight Into ZnO NWs Memristive Behavior

“…A (3 × 3 × 1) Monkhorst−Pack grid was used for the Brillouin zone sampling. The PES was obtained by placing a Cu adatom at several (15 evenly spaced grid points) inequivalent positions in the irreducible part of the (2 × 2) surface cell at an initial distance from the surface atoms of 2.5 Å, as proposed by Aliano et al 30 At each position, the z-coordinate (perpendicular to the surface plane) of the adatom was relaxed together with each coordinate of the atoms in the substrate until forces were smaller than 26 meV/Å. To analyze the electronic properties of the Cu-covered ZnO surfaces, a Hubbard-U correction was applied to the relaxed systems.…”