High-performance ZnO-Pr6O11 thin-film varistors were fabricated simply by hot-dipping oxygen-deficient zinc oxide thin films in Pr6O11 powder. The films had a composition of ZnO0.81 and a thickness of about 200 nm, which were deposited by radio frequency magnetron sputtering a sintered zinc oxide ceramic target. Special attention was paid on the temperature dependence of the varistors. In 50 min with hot-dipping temperature increased from 300–700 °C, the nonlinear coefficient (α) of the varistors increased, but with higher temperature it decreased again. Correspondingly, the leakage current (IL) decreased first and then increased, owing mainly to the formation and destroying of complete zinc oxide/Pr6O11 grain boundaries. The breakdown field (E1mA) decreased monotonously from 0.02217 to 0.01623 Vm with increasing temperature (300–800 °C), due to the decreased number of effective grain boundaries in the varistors. The varistors prepared at 700 °C exhibited the optimum nonlinear properties with the highest α = 39.29, lowest IL = 0.02736 mA/cm2, and E1mA = 0.01757 Vm. And after charge-discharge at room temperature for 1000 times, heating at 100 or 250 °C for up to 100 h, or applying at up to 250 °C, the varistors still performed well. Such nanoscaled thin-film varistors will be very promising in electrical/electronic devices working at low voltage.
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机译:高性能ZnO-Pr6O11薄膜压敏电阻是通过在Pr6O11粉末中热浸缺氧的氧化锌薄膜而简单制造的。该膜的成分为ZnO0.81,厚度约为200 nm,是通过射频磁控溅射法沉积烧结的氧化锌陶瓷靶而形成的。特别关注压敏电阻的温度依赖性。在热浸温度从300–700 C升高到50 min时,压敏电阻的非线性系数(α)增大,但随着温度的升高,其非线性系数再次降低。相应地,漏电流(IL)先减小然后增大,这主要是由于形成和破坏了完整的氧化锌/ Pr6O11晶界。随着压敏电阻中有效晶界数量的减少,击穿场(E1mA)从0.02217下降至0.01623 V / nm,且温度升高(300–800°C)。在700℃下制备的压敏电阻表现出最佳的非线性特性,最高α= 39.29,最低IL = 0.02736 mA / cm 2 sup>,E1mA = 0.01757 V / nm。并且在室温下充放电1000次,在100或250 C加热达100 h或在最高250 C加热后,压敏电阻仍然表现良好。这种纳米级薄膜压敏电阻在低压工作的电气/电子设备中将是非常有前途的。
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