Abstract
We report density functional calculations that clarify atom-scale mechanisms of vapor-phase epitaxial growth of GaN with gas sources of trimethylgallium and ammonia. We identify various stable adsorption structures of a Ga atom and NHx molecules (x = 0-3) on GaN(0001) surfaces and find that NH2 and NH units spontaneously intervene in Ga-Ga surface bonds on Ga-rich GaN(0001) surface. We then explore the reaction in which NH3 on the surface is decomposed and becomes an N-incorporated structure, -Ga-(NH)-Ga-, on the Ga-rich GaN(0001) and find that the reaction occurs with the energy barrier of 0.63 eV. Further exploration reveals that a reaction of H2 desorption occurs with the energy barrier of 2 eV, leaving the N atom incorporated in the Ga-N network. This barrier can be overcome when we consider the chemical potential of an H2 molecule in the gas phase at the growth temperature. This N incorporation on GaN is a new growth mechanism catalyzed by the growing surface.
| Original language | English |
|---|---|
| Pages (from-to) | 24665-24671 |
| Number of pages | 7 |
| Journal | Journal of Physical Chemistry C |
| Volume | 122 |
| Issue number | 43 |
| DOIs | |
| Publication status | Published - Nov 1 2018 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
Cite this
Reaction Pathway of Surface-Catalyzed Ammonia Decomposition and Nitrogen Incorporation in Epitaxial Growth of Gallium Nitride. / Bui, Kieu My; Iwata, Jun Ichi; Kangawa, Yoshihiro; Shiraishi, Kenji; Shigeta, Yasuteru; Oshiyama, Atsushi.
In: Journal of Physical Chemistry C, Vol. 122, No. 43, 01.11.2018, p. 24665-24671.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Reaction Pathway of Surface-Catalyzed Ammonia Decomposition and Nitrogen Incorporation in Epitaxial Growth of Gallium Nitride
AU - Bui, Kieu My
AU - Iwata, Jun Ichi
AU - Kangawa, Yoshihiro
AU - Shiraishi, Kenji
AU - Shigeta, Yasuteru
AU - Oshiyama, Atsushi
PY - 2018/11/1
Y1 - 2018/11/1
N2 - We report density functional calculations that clarify atom-scale mechanisms of vapor-phase epitaxial growth of GaN with gas sources of trimethylgallium and ammonia. We identify various stable adsorption structures of a Ga atom and NHx molecules (x = 0-3) on GaN(0001) surfaces and find that NH2 and NH units spontaneously intervene in Ga-Ga surface bonds on Ga-rich GaN(0001) surface. We then explore the reaction in which NH3 on the surface is decomposed and becomes an N-incorporated structure, -Ga-(NH)-Ga-, on the Ga-rich GaN(0001) and find that the reaction occurs with the energy barrier of 0.63 eV. Further exploration reveals that a reaction of H2 desorption occurs with the energy barrier of 2 eV, leaving the N atom incorporated in the Ga-N network. This barrier can be overcome when we consider the chemical potential of an H2 molecule in the gas phase at the growth temperature. This N incorporation on GaN is a new growth mechanism catalyzed by the growing surface.
AB - We report density functional calculations that clarify atom-scale mechanisms of vapor-phase epitaxial growth of GaN with gas sources of trimethylgallium and ammonia. We identify various stable adsorption structures of a Ga atom and NHx molecules (x = 0-3) on GaN(0001) surfaces and find that NH2 and NH units spontaneously intervene in Ga-Ga surface bonds on Ga-rich GaN(0001) surface. We then explore the reaction in which NH3 on the surface is decomposed and becomes an N-incorporated structure, -Ga-(NH)-Ga-, on the Ga-rich GaN(0001) and find that the reaction occurs with the energy barrier of 0.63 eV. Further exploration reveals that a reaction of H2 desorption occurs with the energy barrier of 2 eV, leaving the N atom incorporated in the Ga-N network. This barrier can be overcome when we consider the chemical potential of an H2 molecule in the gas phase at the growth temperature. This N incorporation on GaN is a new growth mechanism catalyzed by the growing surface.
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U2 - 10.1021/acs.jpcc.8b05682
DO - 10.1021/acs.jpcc.8b05682
M3 - Article
AN - SCOPUS:85056091409
VL - 122
SP - 24665
EP - 24671
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 43
ER -