The thermodynamic, electronic and optical properties of GeP type ZnO under pressure calculated by Debye model and hybrid function

We used the quasi-harmonic Debye model and hybrid function (HSE) to calculate the thermal, electronic and optical properties of GeP type ZnO. The GeP type ZnO has been predicted by theory recently. HSE method is suited for the strongly correlated ZnO. Our calculated enthalpies show wurtzite type (B4) transforms to GeP type at 8.8 GPa. We calculated bands of GeP type ZnO under pressure and used an equation to fit the relation between band gaps and pressure. The electronic density of states (DOS) of B4, GeP and B1 type ZnO under pressure were calculated. And relations between DOS and bands have been discussed. The imaginary part (ε2(ω)) of the dielectric function shows the GeP type ZnO can be used in the ultraviolet region. From the real part ε1(ω) of the dielectric function, GeP type ZnO exhibits metallic character around 23.0 eV. Metallic behavior should be notice in the future applications. With increasing pressure, the optical properties shift to higher energy (blue shift), which can be used to evaluate pressure after calibration. We took the absorption coefficient (α(ω)) as an example and used an equation to fit the relation between α(ω) and pressure. The equations about bandgap and α(ω) with pressure can be used to evaluate pressure after calibration. Our paper provides a reference for the applications of GeP type ZnO in the future.