Strain regulation of optical properties of 2D 6H-SiC
In order to reduce band gap of 6H-SiC and improve the absorption efficiency of visible light and car-rier mobility,the effects of strain on the band structure,optical absorption coefficient,carrier mobility and pho-tocatalytic properties of 6H-SiC were studied by using the first principle method.The results indicate that strain can reduce the conduction band minimum(CBM)of 6H-SiC,but has no effect on the valence band maximum(VBM),resulting in the reduction of band gap.With the increase of strain,the absorption curve moves to the low energy level(red shift),which is beneficial for the absorption of visible light.After the strain is applied,the carrier mobility of the hole is improved,which is conducive to the carrier movement,and the carrier mobility of the hole is 2.5 times that of the electron,which is conducive to the separation of the hole and the electron.According to the influence of strain on band gap and band edge position,the strains of±2％and±4％are the most effective conditions for visible light absorption and photocatalytic hydrogen generation.In conclusion,the strain can well regulate the optical absorption and photocatalytic properties of 6H-SiC.
万方数据
维普
