Theoretical study of intrinsic defects in CdTe

19th Chilean Physics Symposium 2014

Menéndez-Proupin, E.^1 ; Orellana, W.^2

Departamento de Física, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Ñuñoa Santiago

780-0003, Chile^1

Departamento de Ciencias Físicas, Universidad Andres Bello, República 220, Santiago

037-0134, Chile^2

关键词: Brillouin zones;    First-principles calculation;    Formation energies;    Intrinsic defects;    K-point sampling;    Perfect crystals;    Theoretical study;    Thermodynamical properties;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/720/1/012031/pdf
DOI  :  10.1088/1742-6596/720/1/012031

来源: IOP

【 摘 要 】

The quantum states and thermodynamical properties of the Cd and Te vacancies in CdTe are studied by first principles calculations. It is shown that the band structure of a cubic 64-atoms supercell with a Te vacancy is dramatically different from the band structure of the perfect crystal, suggesting that it cannot be used as model to calculate isolated defects. This flaw is solved modeling the Te vacancy within a cubic 216-atoms supercell. However, even with this large supercell, the 2 - charge state relaxes to an incorrect distorted structure. This distortion is driven by partial filling of the conduction band induced by the k-point sampling. The correct structures and formation energies are obtained by relaxation with restriction of system symmetry, followed by band-filling correction to the energy, or by using a larger supercell that allows sampling the Brillouin zone with a single k-point.