The properties of GaAs:
The phonon spectrum, band structure, electronic density of States and optical properties of two-dimensional GaAs are studied by using the plane wave method based on density functional theory and molecular dynamics theory. It is found that two-dimensional GaAs and graphene are similar in structure. Phonon spectrum shows that there is no virtual frequency in two-dimensional graphene like GaAs and the model is stable. Compared with three-dimensional GaAs, two-dimensional GaAs has overlapping energy bands, metal properties and significantly enhanced conductivity. The above phenomenon is mainly due to the decrease of dimension, which makes the interaction between S-state and p-state electrons of as increase, and the peak of density of States moves to the range of low energy band and high energy band; The low energy band is mainly composed of D state of GA, s state and P state of as, and the high energy band is mainly composed of s state and P state of as
The electronic structures of semiconductor GaAs sphalerite structures under different pressures are calculated by density functional theory. The lattice constant, total energy, bond length and band structure are obtained. The critical pressure for the transition from direct band gap structure to indirect band gap structure is 8.65 GPA, which is in good agreement with the experimental values, The electronic structure and electrical properties of GaAs under high pressure are discussed in detail.
Ga atom/unit cell number density=4/(5.65 times 10-s) 3 Ga atom density=2.22 times 1022 cm-3 4 As atom/unit cell number density=2.22 times 1022 cm-3 8 Ge Atom/unit cell number density=8/(5.65 times 10-s) 3
The calculation results of optical properties show that the static dielectric constant of two-dimensional GaAs is 3.67, and there are four absorption peaks in the imaginary part of the dielectric function; In the energy range of 3.90 ~ 4.71 EV and 5.69 ~ 6.90 EV, the material shows metal reflection characteristics to ultraviolet light. The material has a certain absorption and reflection effect to ultraviolet light in a specific energy range. It can be used to make optical storage devices, as well as UV shielding or UV detector devices.