Electrical Properties of Li-doped P-type ZnO Ceramics

Li-doped p-type ZnO ceramics were prepared by conventional methods according to the chemical formula Zn1-xLixO2 where x=0.5, 1.0, 1.5 and 2.0 mole fraction, respectively.The crystal structures of the prepared samples were studied by X-ray diffraction analysis.The dielectric properties (including dielectric constant ε'and dielectric loss ε") and dc-electrical conductivity [σ(Ω-1.cm-1)] were investigated.The dielectric constant ε' was sharply decreased at the low frequency range and independent on frequency at high frequency range.Otherwise, the dielectric loss ε" varied with frequency and showed absorption peak located from 200 Hz to 4 kHz and moved to higher frequency as the concentration of Li+ doped increased.It was found that dcelectrical conductivity logσ varied from -9 to -5 and the energy gap width were calculated by using Arrhenius equation.The p-type conductivity of Li-doped ZnO may be attributed to the formation of a Lizn-Lii donor complex, which is limited by reducing the amount of Lii.