氧化鋅變阻　器具有優越的電流-電壓非歐姆特性(non-ohmic characteristics)和突波吸收能力，因此被廣泛應用在電子和固態電子元牛上，作為穩壓及吸收突波的保護裝置。
　　本研究利用電泳沉積法製備氧化鋅薄膜，並藉由硝酸鉍電解質之添加進行金屬鉍共鍍。探討電泳參數對於鍍層成長特性、化學組成、微結構之影響，以SEM、EDS、XRD分析鍍層的表面形態、元素組成分佈及相變化，量測I-V曲線，探討變阻特性。
　　研究結果顯示在電泳沉積氧化鋅時，伴隨著鉍離子電化學還原，在陰極基板析出鉍金屬。鍍層之厚度、鉍金屬含量及鍍層的表面形態，可利用改變電泳製程參數而獲得控制。其中鉍離子部份吸附在氧化鋅顆粒表面共沉積，鉍金屬在燒結中氧化成氧化鉍，藉由此種形態，將導致燒結時形成氧化鋅晶粒被氧化鉍包覆的效果，達到適合做為氧化鋅變阻器之微結構。
　　而本研究首次嘗試以電泳沉積氧化鋅共鍍鉍金屬，作為製備氧化鋅變阻器之製程，相較於傳統製程可獲得更適於做為氧化鋅變阻器之
微結構特徵，α值為評估變阻特性之指標，實驗量測之α值在燒結溫度900℃約為10，接近目前以氧化鋅-氧化鉍作為變阻器材料所得範圍(5~10)之最大值。

　　In this study, the ZnO coatings co-deposited with metallic Bi coming from electrolyte were fabricated by electrophoretic deposition (EPD). The effect of electrophoretic parameters on the deposit characteristics, such as deposition kinetics, the composition of coatings and microstructure were evaluated by SEM, EDS and XRD. Besides, the measurement of I-V curve has also been conducted to determine the non-ohmic characteristics of the varistor fabricated.
　　Experimental results show that the electrophoretic deposition of ZnO particles accompanies the reduction of bismuth ion in the form of bismuth metal onto the cathode substrate at appropriate conditions. The thickness, composition and morphology of the deposited layers can be well controlled by proper selection of deposition parameters. Bismuth metal dispersed homogeneously within ZnO coatings as a result of cathodic reduction of ions from those adsorbed on the surface of ZnO particle. During the liquid phase sintering process, ZnO grains are separated by bismuth oxide layer derived from oxidization of bismuth metal and make it suitable for ZnO varistor.
In this work, for the first time, ZnO varistor is fabricated by combining the EPD of ZnO nanoparticles and the co-deposition of a specific additive from the electrolyte. As verified from the result, the microstructure and composition suitable for ZnO varistor is obtained. By using this process, the α value is about 10 for ZnO sintered at 900℃ for 2 h, which approaches the maximum value for the ZnO-Bi2O3 binary system reported.

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