掺杂Al_2O_3纳米粉对ZnO厚膜气敏传感器性能的影响

Effect of Al_2O_3 doping on the sensing performance of ZnO thick film gas sensors

以ZnO纳米粉(平均粒径30 nm)和A l2O3纳米粉(平均粒径5 nm)为原料,利用传统的厚膜气敏传感器制备工艺制备了纯ZnO厚膜气敏传感器和掺杂A l2O3(掺杂量为2wt%和5wt%)的ZnO厚膜气敏传感器。对这三种厚膜传感器的本征电阻及对乙醇蒸汽的敏感特性进行了测试。结果表明:掺杂少量A l2O3纳米粉可明显降低ZnO气敏传感器的本征电阻,改善传感器的烧结性能,同时还可降低其最佳工作温度,提高器件对乙醇的灵敏度。结合厚膜气敏传感器的显微结构分析结果,对出现上述差异的原因进行了讨论。

By a conventional preparation method of thick film gas sensor, pure ZnO thick film sensors and two Al2O3 - doped （ the contents of Al2O3 are 2wt% and 5wt% respectively） ZnO thick film sensors were fabricated from ZnO （with average particle size of 30 nm） and Al2O3 nanoparticles （the average particle size was 5 nm）. The intrinsic resistances and gas sensing performance of the samples to ethanol vapor were tested. The results indicate that the intrinsic resistances and the working temperatures of ZnO gas sensors decrease with the doping of Al2O3. At the same time, the sintering properties and the sensitivities of these gas sensors are improved. Furthermore, the reason for the above improvement is analyzed on the basis of morphology observation of these thick film sensors.