Research Of ZnSe And ZnTe Electrical Properties And Reversible Phase Transition Under High Pressure

The optical properties of II-VI group semiconductor, such as new type lamp-house, spin electronics, integration optical path, optoelectronics & photon crystalloid, etc. draw a lot of attention recently. Their electric properties, especially under ultrahigh pressure condition, are what we are caring about. So we take ZnSe & ZnTe as our samples.The pressure goes from atmospheric pressure to nearly 20 GPa. Sample's resistance is calculated by using Van de Pauw method. From the resistance data of ZnSe we know that the structure of ZnSe remains znic-blende before 13.1GPa and becomes rock salt after 13.5GPa. The metallic phase transition point is at 17.0GPa. We can tell from the resistance data of ZnTe that it's structure is transformed from znic-blende to cinnabar then to Cmcm & it's metallic phase transition pressure is at 12.5GPa. Under the decompression, the resistance returned to the initial one. So the phase transition is reversible.Meanwhile, sample's impedance, which shows the same trend of resistance transformation measured under direct current, is measured under the range from 1Hz to 32MHz. It is an assistant explanation to the resistance measured before under direct current.