Enhanced radial growth of Mg doped GaN nanorods

A combined experimental and first-principles study

Sanjay Nayak, Rajendra Kumar, Nidhi Pandey, K. K. Nagaraja, Mukul Gupta, S. M. Shivaprasad

Research output: Contribution to journalArticle

Abstract

We discuss the microstructural origin of enhanced radial growth in magnesium (Mg) doped single crystalline wurtzite gallium nitride (w-GaN) nanorods (NRs) grown by MBE, using electron microscopy and first-principles Density Functional Theory calculations. Experimentally, we observe that Mg incorporation increases the surface coverage of the grown samples as a consequence of an increase in the radial growth rate of the NRs. We also observe that the coalescence of NRs becomes prominent and the height at which coalescence between proximal rods occurs decreases with increase in Mg concentration. From first-principles calculations, we find that the surface free energy of the Mg doped surface reduces with increasing Mg concentration in the samples. The calculations further suggest a reduction in the adsorption energy and the diffusion barrier of Ga adatoms along [1120] on the side wall surface of the NRs as the underlying mechanism for the observed enhancement in the radial growth rate of GaN NRs. The physics and chemistry behind reduction of the adsorption energy of Ga ad-atoms on the doped surface are explained in the light of electronic structure of the relevant surfaces.

Original languageEnglish
Article number135303
JournalJournal of Applied Physics
Volume123
Issue number13
DOIs
Publication statusPublished - 07-04-2018

Fingerprint

nanorods
magnesium
coalescing
adsorption
gallium nitrides
wurtzite
adatoms
electron microscopy
rods
free energy
density functional theory
electronic structure
physics
energy
augmentation
atoms

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Nayak, Sanjay ; Kumar, Rajendra ; Pandey, Nidhi ; Nagaraja, K. K. ; Gupta, Mukul ; Shivaprasad, S. M. / Enhanced radial growth of Mg doped GaN nanorods : A combined experimental and first-principles study. In: Journal of Applied Physics. 2018 ; Vol. 123, No. 13.
@article{a4bf4c384ea64f0db2c859d02467fd7e,
title = "Enhanced radial growth of Mg doped GaN nanorods: A combined experimental and first-principles study",
abstract = "We discuss the microstructural origin of enhanced radial growth in magnesium (Mg) doped single crystalline wurtzite gallium nitride (w-GaN) nanorods (NRs) grown by MBE, using electron microscopy and first-principles Density Functional Theory calculations. Experimentally, we observe that Mg incorporation increases the surface coverage of the grown samples as a consequence of an increase in the radial growth rate of the NRs. We also observe that the coalescence of NRs becomes prominent and the height at which coalescence between proximal rods occurs decreases with increase in Mg concentration. From first-principles calculations, we find that the surface free energy of the Mg doped surface reduces with increasing Mg concentration in the samples. The calculations further suggest a reduction in the adsorption energy and the diffusion barrier of Ga adatoms along [1120] on the side wall surface of the NRs as the underlying mechanism for the observed enhancement in the radial growth rate of GaN NRs. The physics and chemistry behind reduction of the adsorption energy of Ga ad-atoms on the doped surface are explained in the light of electronic structure of the relevant surfaces.",
author = "Sanjay Nayak and Rajendra Kumar and Nidhi Pandey and Nagaraja, {K. K.} and Mukul Gupta and Shivaprasad, {S. M.}",
year = "2018",
month = "4",
day = "7",
doi = "10.1063/1.5024278",
language = "English",
volume = "123",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics Publising LLC",
number = "13",

}

Enhanced radial growth of Mg doped GaN nanorods : A combined experimental and first-principles study. / Nayak, Sanjay; Kumar, Rajendra; Pandey, Nidhi; Nagaraja, K. K.; Gupta, Mukul; Shivaprasad, S. M.

In: Journal of Applied Physics, Vol. 123, No. 13, 135303, 07.04.2018.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Enhanced radial growth of Mg doped GaN nanorods

T2 - A combined experimental and first-principles study

AU - Nayak, Sanjay

AU - Kumar, Rajendra

AU - Pandey, Nidhi

AU - Nagaraja, K. K.

AU - Gupta, Mukul

AU - Shivaprasad, S. M.

PY - 2018/4/7

Y1 - 2018/4/7

N2 - We discuss the microstructural origin of enhanced radial growth in magnesium (Mg) doped single crystalline wurtzite gallium nitride (w-GaN) nanorods (NRs) grown by MBE, using electron microscopy and first-principles Density Functional Theory calculations. Experimentally, we observe that Mg incorporation increases the surface coverage of the grown samples as a consequence of an increase in the radial growth rate of the NRs. We also observe that the coalescence of NRs becomes prominent and the height at which coalescence between proximal rods occurs decreases with increase in Mg concentration. From first-principles calculations, we find that the surface free energy of the Mg doped surface reduces with increasing Mg concentration in the samples. The calculations further suggest a reduction in the adsorption energy and the diffusion barrier of Ga adatoms along [1120] on the side wall surface of the NRs as the underlying mechanism for the observed enhancement in the radial growth rate of GaN NRs. The physics and chemistry behind reduction of the adsorption energy of Ga ad-atoms on the doped surface are explained in the light of electronic structure of the relevant surfaces.

AB - We discuss the microstructural origin of enhanced radial growth in magnesium (Mg) doped single crystalline wurtzite gallium nitride (w-GaN) nanorods (NRs) grown by MBE, using electron microscopy and first-principles Density Functional Theory calculations. Experimentally, we observe that Mg incorporation increases the surface coverage of the grown samples as a consequence of an increase in the radial growth rate of the NRs. We also observe that the coalescence of NRs becomes prominent and the height at which coalescence between proximal rods occurs decreases with increase in Mg concentration. From first-principles calculations, we find that the surface free energy of the Mg doped surface reduces with increasing Mg concentration in the samples. The calculations further suggest a reduction in the adsorption energy and the diffusion barrier of Ga adatoms along [1120] on the side wall surface of the NRs as the underlying mechanism for the observed enhancement in the radial growth rate of GaN NRs. The physics and chemistry behind reduction of the adsorption energy of Ga ad-atoms on the doped surface are explained in the light of electronic structure of the relevant surfaces.

UR - http://www.scopus.com/inward/record.url?scp=85045315800&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85045315800&partnerID=8YFLogxK

U2 - 10.1063/1.5024278

DO - 10.1063/1.5024278

M3 - Article

VL - 123

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

IS - 13

M1 - 135303

ER -