shiva mokhavat

In this paper, the structural, electronic and pressure characteristics of GaP composition in different phases have been investigated. The calculations are performed using the pseudopotential method, in the framework of density functional theory, and  PWscf code. The pseudopotentials applied here are generated using norm-conserving condition within LDA and GGA for exchange correlation functional. The results of the compressibility indicate that as the pressure increased from Zincblend to Cmcm phase the hardness of compound is increased. Investigation of Energy –Volume curves shows that the cinnabar phase is metastable. The study of the band structures suggests that this compound is a semiconductor in Zincblend and Cinnabar phase with indirect band gap and is a metal in Cmcm phase.  The electron density also indicates the covalent bond between the Ga and P atoms.

In this paper, the optical properties of GaP in different phases have been investigated. The calculations were performed by using pseudopotential in the framework of density functional theory and using the PWscf code. The pseudopotentials applied here are generated using norm-conserving conditions within GGA for the exchange-correlation function. The optical properties of the Zincblend and Cinnabar phases reveal the conformity between the band structure and the imaginary part of the dielectric function, and the band gap and optical gap are almost equal. The refractive index obtained from the real part of the dielectric function in Zincblend is 3.306 and in the Cinnabar phase is 4.235 and 3.808 in the x and z directions, respectively.