研究目的
Investigating the influence of compression strains on photon absorption of silicene and germanene using density functional theory.
研究成果
Compressive strain increases optical absorption in silicene and germanene, reduces the band gap at Dirac points to zero, and causes red and blue shifts in absorption peaks depending on strain magnitude and light polarization direction. Anisotropy in absorption is due to energy band anisotropy, with higher absorption along the zigzag direction. Strain acts oppositely to electric fields by closing the band gap.
研究不足
The study is based on computational simulations using DFT, which may have approximations in exchange-correlation functionals. Experimental validation is not provided, and the linear profile assumed for buckling-strain dependence might not capture all nuances. The focus is on homogeneous compressive strain, and other types of strain or external factors are not considered.
1：Experimental Design and Method Selection:
The study uses density functional theory (DFT) with the ABINIT computational package to investigate optical properties under compressive strain. Local density approximation (LDA) is used for exchange-correlation, and Martins-Trouiller pseudo-potentials for atomic core-potentials.
2：Sample Selection and Data Sources:
Silicene and germanene structures are modeled with parameters from literature, including lattice constants, bonding lengths, and buckling heights.
3：List of Experimental Equipment and Materials:
Computational tools and software (ABINIT package) are used; no physical equipment is mentioned.
4：Experimental Procedures and Operational Workflow:
Calculations involve discretizing the first Brillouin zone using a 42x42x1 k-space sampling, optimizing cut-off energy to 30 Hartree, and including a vacuum space of 20 ? to prevent inter-layer interactions. Optical absorption is computed for zigzag and armchair directions.
5：Data Analysis Methods:
Imaginary part of the dielectric function is analyzed to measure light absorption, with results plotted and compared for different strain levels.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
