Computational studies of positron states and annihilation parameters in semiconductors _ vacancy-type defects in group-III nitrides _

The International Workshop on Positron Studies of Defects 2014

Ishibashi, S.^1 ; Uedono, A.^2

Nanosystem Research Institute (NRI), RICS, National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki, Tsukuba

305-8568, Japan^1

Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Ibaraki, Tsukuba

305-8573, Japan^2

关键词: Computational studies;    Conventional schemes;    Dilute magnetic semiconductors;    Group III nitrides;    Positron annihilation technique;    Positron state;    Special quasi-random structures;    Vacancy-type defects;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/674/1/012020/pdf
DOI  :  10.1088/1742-6596/674/1/012020

来源: IOP

【 摘 要 】

We have computationally studied positron sates and annihilation parameters in semiconductors, especially in group-III nitrides. A random alloy system In0.5Ga0.5N was model with the special-quasirandom-structure scheme and distributions of annihilation parameters for cation monovacancies and divacancies were investigated. On GaN, we calculated annihilation parameters considering spin polarization for Ga vacancies with various charge sate and demonstrated how the positron annihilation technique is useful to study defect-induced or mediated magnetism in dilute magnetic semiconductors. We also made calculations based on the two-component density functional theory and compared their results with those obtained by the conventional scheme.