Density Functional Theory Analysis of the Electronic and Optical Properties of Si-modified AlN Monolayer
Using the density functional theory,this paper studied the electronic structure and op-tical properties of Si-modified AlN monolayer.The calculation results found that Si modifica-tion introduced new impurity levels near the Fermi level,which reduced the band gap from 2.894 eV to 0.944 eV,making it easier for the valence band electrons to jump to the conduction band.At the same time,Si modification also caused the spin splitting of the AlN monolayer's band,and the electron density of states curves of spin-up and spin-down were asymmetric,indi-cating that the system changed from intrinsic non-magnetic to Si-modified magnetic.This was due to the introduction of multiple asymmetric spin-up and spin-down density of states peaks by Si elements near the Fermi level.The optical properties calculation results showed that the ab-sorption wavelength threshold of AlN monolayer was in the ultraviolet region under the intrin-sic state,and it red-shifted to the visible region after Si modification.The research results showed that Si-modified AlN monolayer could utilize the visible light band,improve its effi-ciency in photocatalysis,and was expected to be used to make visible light band responsive opto-electronic sensors and spintronic devices.