Electrical properties and stability of Tb-doped zinc oxide-based nonlinear resistors

The microstructure, electric field–current density ( E – J ), capacitance–voltage ( C – V ), and stability characteristics of Zn–Pr–Co–Cr–Tb oxide-based nonlinear resistors were investigated for different Tb4O7 amounts. It increased in the range of 8.9–42.0 in the nonlinear coefficient and in the range of 1026–6514 V/cm in the breakdown field with increasing Tb4O7 amount. As Tb4O7 amount increased, the donor density decreased in the range of 1.23×1018–0.70×1018/cm3, whereas the barrier height at grain boundaries increased in the range of 0.73–0.93 eV. A good stability was obtained in the range of 0.25–0.5 mol% in Tb4O7 amount.