高能球磨和低温烧结制备高电位梯度ZnO厚膜压敏电阻

Preparation of High Potential Gradient ZnO-Based Thick-Film Varistors by High-Energy Ball Milling and Low-temperature Sintering

通过高能球磨和低温烧结,制备出高电位梯度的ZnO厚膜压敏电阻,并研究了烧结温度对厚膜试样电学性能的影响。结果表明,高能球磨可显著细化粉体颗粒,球磨后颗粒的平均尺寸减小到0.420μm;颗粒的高度细化促使厚膜可在650～850℃的低温范围烧结成瓷,其中在700℃的烧结条件下,厚膜试样的综合性能最佳,电位梯度达到3175.6 V.mm-1,漏电流为30.7μA,非线性系数为13,微观势垒高度为0.79 eV,耗尽层宽度为14.4 nm,施主浓度为2.24×1018 cm-3,表面态密度为3.22×1012 cm-2。

The high potential gradient ZnO-based thick-film varistors were fabricated by high-energy ball milling and low-temperature sintering.The effect of sintering temperature on electrical properties was investigated.The results showed that the high-energy ball milling in the early period of experiment reduced the average particle size to 0.420 μm.The high refined particles realized the sintering of ceramics at a relatively lower temperature range of 650~850 ℃.The sample sintered at 700 ℃ exhibited excellent electrical properties,with a potential gradient of 3175.6 V·mm-1,a leakage current of 30.7 μA,a nonlinear exponent of 13.1,a barrier height of 0.79 eV,a depletion layer width of 14.4 nm,a donor density of 2.24×1018 cm-3,and an interface states density of 3.22×1012 cm-2.