Role and dynamical evolution of intrinsic divacancies in the growth process of epitaxial GaN
Abstract
The presence of defect complexes, namely the VN-VGa divacancy, in metal-organic vapor phase epitaxy grown GaN systems translates into device degradation with severe consequences particularly important in power electronics applications. To get an insight into the behavior of this type of defects, we resort to long-lasting first principles simulations to characterize the dynamical behavior and underlying electronic structure of VN-VGa divacancies at the experimental temperature used to produce GaN. We evidence a peculiar mechanism, triggered by temperature, in which the diffusion of a Ga atom around the divacancy promotes the displacement of the defect and a switching mechanism, not accompanied by N atoms diffusion. These processes, occurring below the surface layer, do not affect the surface growth reactions such as the uptake and binding of an NH2 moiety, thus being of negligible importance for the epitaxy of the material. The divacancy can switch from different configurations, co-planar or involving two adjacent layers below the (0001) surface, generating persistent gap states that can become charge trap centers.
Related
- Microscopic description of the fission process including intrinsic excitations. Part I: 240Pu adiabatic and asymmetric fission path within the Schrodinger Collective Intrinsic Model
- Microscopic description of the fission process including intrinsic excitations. Part III: 240Pu fission dynamics along 1D asymmetric paths within the Schrodinger Collective Intrinsic Model
- Microscopic description of the fission process including intrinsic excitations. Part II: 240Pu excited and asymmetric fission paths within the Schrodinger Collective
- Intrinsic dynamical shadowing of point vortices and finite time singularities
- Intrinsic evolution pathway connecting two quasi-steady dissipative soliton states in a pulsating Yb-doped fiber laser
BibTeX
@article{ishisone2026role,
title = {{Role and dynamical evolution of intrinsic divacancies in the growth process of epitaxial GaN}},
author = {Kana Ishisone and Akira Kusaba and Yoshihiro Kangawa and Mauro Boero},
journal = {Applied Surface Science},
year = {2026},
month = oct,
doi = {10.1016/j.apsusc.2026.168722},
url = {https://hal.science/hal-05836219v1},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Role and dynamical evolution of intrinsic divacancies in the growth process of epitaxial GaN
AU - Kana Ishisone
AU - Akira Kusaba
AU - Yoshihiro Kangawa
AU - Mauro Boero
PY - 2026
DA - 2026/10/20
JO - Applied Surface Science
DO - 10.1016/j.apsusc.2026.168722
UR - https://hal.science/hal-05836219v1
AB - The presence of defect complexes, namely the VN-VGa divacancy, in metal-organic vapor phase epitaxy grown GaN systems translates into device degradation with severe consequences particularly important in power electronics applications. To get an insight into the behavior of this type of defects, we resort to long-lasting first principles simulations to characterize the dynamical behavior and underlying electronic structure of VN-VGa divacancies at the experimental temperature used to produce GaN. We evidence a peculiar mechanism, triggered by temperature, in which the diffusion of a Ga atom around the divacancy promotes the displacement of the defect and a switching mechanism, not accompanied by N atoms diffusion. These processes, occurring below the surface layer, do not affect the surface growth reactions such as the uptake and binding of an NH2 moiety, thus being of negligible importance for the epitaxy of the material. The divacancy can switch from different configurations, co-planar or involving two adjacent layers below the (0001) surface, generating persistent gap states that can become charge trap centers.
SN - 0169-4332
SN - 1873-5584
ER -