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2025-06-28 14:16:36 +08:00
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@@ -8,7 +8,7 @@
* [x] 中文
* [x] 英文
* [x] 调整语言
* [ ] 模型总述
* [x] 模型总述
* [ ] 无缺陷和点缺陷的模型大小、结构
* [x] 中文
* [ ] 英文

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@@ -64,34 +64,25 @@ Three types of models were established: defect-free models, point defect models,
此结构除了 h 位与 k 位的区别以外,还需要考虑发生替换的两个原子位于面内还是面外(将会导致对称性的不同)。
The defect-free and point defect models were established
with a size of $12.4 #sym.angstrom times 10.7 #sym.angstrom times 10.1 #sym.angstrom$,
with dimensions of $12.4 #sym.angstrom times 10.7 #sym.angstrom times 10.1 #sym.angstrom$,
containing approximately 128 atoms.
This size should be large enough to calculate phonon properties for defect-free and point defect 4H-SiC,
since the defect-free results obtained with these models were within 5% errors of the experimental data,
and further increasing the model size did not improve the accuracy.
Twelve point defect models were considered, including Si vacancies (V#sub[Si]),
C vacancies (V#sub[C]), nitrogen substitutions (N#sub[Si]), and aluminum substitutions (Al#sub[C]).
Considering the symmetry of 4H-SiC, which is p63mc (cite),
there are two different sites, k and h,
which can be approximated as cubic (k) or hexagonal (h) based on the local environment.
For point defect models, we considered five different structures,
including Si vacancies (V#sub[Si]), C vacancies (V#sub[C]),
nitrogen substitutions (N#sub[Si]), aluminum substitutions (Al#sub[C]),
and the structure of a nitrogen substitute carbon and carbon substitute silicon (N#sub[C]C#sub[Si])
which is proposed by xxx (ref) to be a possible structure of nitrogen doping.
Besides,
For surface defect models, larger models where used to ensure the accuracy of the phonon properties.
This supercell size was found sufficient for accurately capturing the phonon properties
of both defect-free and point-defect-containing 4H-SiC,
as the calculated phonon frequencies for the defect-free model deviated by less than 5% from experimental values,
and further increasing the cell size yielded negligible improvements.
Twelve point defect configurations were investigated,
including Si vacancies (V#sub[Si]-h and V#sub[Si]-k), C vacancies (V#sub[C]-h and V#sub[C]-k),
nitrogen substitions on C cites (N#sub[C]-h and N#sub[C]-k),
aluminum substitutions on Si cites (Al#sub[Si]-h and Al#sub[Si]-k),
and nitrogen substitutions on C sites followed by C substitutions on Si site
(N#sub[C]C#sub[Si]-i-h, N#sub[C]C#sub[Si]-i-k, N#sub[C]C#sub[Si]-o-h and N#sub[C]C#sub[Si]-o-k),
where -h and -k denote the quasi-hexagonal and quasi-cubic sites,
and -i and -o denote the in-plane and out-of-plane configurations, respectively.
a k 位与 h 位对比 b 面内与面外对比)
For surface defect models, larger models where used to ensure the accuracy of the phonon properties.
因此对于无缺陷和点缺陷的模型,我们使用 xxA x xxA x xxA 的模型大小。