QU Yi-pu, CHEN Xue, WANG Fang etc. Effects of Point Defects on Electronic Structure and Optical Properties of Al<sub>0.5</sub>Ga<sub>0.5</sub>N Nanosheets: First-principles Investigation[J]. Chinese Journal of Luminescence, 2019,40(8): 979-986
QU Yi-pu, CHEN Xue, WANG Fang etc. Effects of Point Defects on Electronic Structure and Optical Properties of Al<sub>0.5</sub>Ga<sub>0.5</sub>N Nanosheets: First-principles Investigation[J]. Chinese Journal of Luminescence, 2019,40(8): 979-986 DOI: 10.3788/fgxb20194008.0979.
Effects of Point Defects on Electronic Structure and Optical Properties of Al0.5Ga0.5N Nanosheets: First-principles Investigation
In order to study the effects of point defects on electronic structure and optical properties of Al
0.5
Ga
0.5
N nanosheets
the classical point defects structures of Al
Ga
N vacancies and N substitute Al and N substitute Ga are established. The method of first-principles ultrasoft pseudopotential based on density functional theory and the GGA-PBE exchange interconnect function are used to calculate the energy band
density of states
complex dielectric function
complex refractive index
absorption spectrum and energy loss spectrum. The results show that the vacancy defects and the substitution defects will lead to the band gap getting narrow. The Al vacancy and the Ga vacancy all make the Fermi level enter the valence band
and the N vacancy makes the nanosheet exhibit n-type properties. The substitution defect will make the nanosheet exhibit semi-metallic properties. In terms of optical properties
the defects lead to produce peaks in the low energy region of the imaginary part of the complex dielectric function of the nanosheet
indicating the occurrence of electronic transitions. At the same time
the vacancy defect causes the absorption spectrum to expand in the low energy region
and the visible light range is also included.
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references
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