Sb_2O_3掺杂对ZnO压敏陶瓷晶界特性和电性能的影响

EFFECT OF Sb_2O_3 DOPING CONTENT ON GRAIN-BOUNDARY CHARACTERISTICS AND ELECTRICAL PROPERTIES OF ZnO VARISTORS

制备了掺有Sb2 O3 不同掺杂量的ZnO压敏陶瓷样品 .采用扫描电镜对样品进行显微结构分析 ,研究了Sb2 O3 掺杂浓度对ZnO压敏电阻显微结构和性能的影响 .测量了样品的电性能 ,由样品C -V特性的测量计算出晶界参数 ,并由此讨论了陶瓷电性能与晶界特性的相关性 .研究发现 ,在ZnO压敏陶瓷样品中掺杂适量的Sb2 O3 可以提高ZnO压敏陶瓷样品的非线性性能 ,但当Sb2 O3 的摩尔分数超过 0 .0 88%时 ,电性能反而劣化 ,这是因为Sb2 O3 掺杂浓度不同会引起晶界势垒高度、施主浓度及陷阱态密度的变化 ,因此Sb2 O3 掺杂量要控制在适当的范围内 .

The ZnO varistor ceramics with different contents of Sb 2O 3 doped were prepared by means of conventional sintering technology. The microstructure of ZnO samples was analyzed by SEM. The effect of Sb 2O 3 dopant content on the electrical properties and grain_boundary characteristics of the ceramics was studied. It is found that the donor density, the density of interface states and the barrier height change with the amount of Sb 2O 3 addition. With a proper content of Sb 2O 3, the breakdown fields and nonlinear coefficient increrase. However, when Sb 2O 3 content surpasses 0.088% (in mole), the nonlinear coefficient of the ZnO ceramics decreases.