The well-developed particle-swarm optimization method together with density functional theory calculations were employed to search lowest-energy geometric structures of two-dimensional(2D)SiGeP_(2).Two newly found str...The well-developed particle-swarm optimization method together with density functional theory calculations were employed to search lowest-energy geometric structures of two-dimensional(2D)SiGeP_(2).Two newly found structures(P3m1 and Pmm2)are predicted.The unbiased global search reveals that the two lowest-energy structures are honeycomb lattices with robust dynamical stabilities.A more accurate Heyd-Scuseria-Ernzerhof(HSE06)hybrid functional is used to estimate the band structures of SiGeP_(2),which indicates that both the structures are semiconductors with indirect band-gap energies 1.80 e V for P3m1 and1.93 e V for Pmm^(2),respectively.Using the deformation potential theory,the P3m1-SiGeP_(2)is predicted to have high electron mobilities(6.4×10^(4)along zigzag direction and 2.9×10^(3)cm^(2)·V^(-1)·s^(-1)along armchair direction,respectively)and hole electron mobilities(1.0×10^(3)along zigzag direction and 2.5×10^(3)cm^(2)·V^(-1)·s^(-1)along armchair direction,respectively),which can be comparable with that of phosphorene and show anisotropic character in-plane.In addition,to estimate the elastic limit of SiGeP_(2),we also calculated the surface tension of SiGeP_(2)as a function of tensile strain.Our results show that the 2D SiGeP_(2)may be good candidaticates for applications in nanoelectronic devices.展开更多
基金Funded by Henan Joint Funds of the National Natural Science Foundation of China(No.U1904179)the National Natural Science Foundation of China(No.51501093)the Key Scientific and Technological Project of Technology Department of Henan Province of China(No.212102210448)。
文摘The well-developed particle-swarm optimization method together with density functional theory calculations were employed to search lowest-energy geometric structures of two-dimensional(2D)SiGeP_(2).Two newly found structures(P3m1 and Pmm2)are predicted.The unbiased global search reveals that the two lowest-energy structures are honeycomb lattices with robust dynamical stabilities.A more accurate Heyd-Scuseria-Ernzerhof(HSE06)hybrid functional is used to estimate the band structures of SiGeP_(2),which indicates that both the structures are semiconductors with indirect band-gap energies 1.80 e V for P3m1 and1.93 e V for Pmm^(2),respectively.Using the deformation potential theory,the P3m1-SiGeP_(2)is predicted to have high electron mobilities(6.4×10^(4)along zigzag direction and 2.9×10^(3)cm^(2)·V^(-1)·s^(-1)along armchair direction,respectively)and hole electron mobilities(1.0×10^(3)along zigzag direction and 2.5×10^(3)cm^(2)·V^(-1)·s^(-1)along armchair direction,respectively),which can be comparable with that of phosphorene and show anisotropic character in-plane.In addition,to estimate the elastic limit of SiGeP_(2),we also calculated the surface tension of SiGeP_(2)as a function of tensile strain.Our results show that the 2D SiGeP_(2)may be good candidaticates for applications in nanoelectronic devices.
