掺杂Fe_2O_3对ZnO多孔纳米固体厚膜气敏传感器性能的影响

Effect of Fe_2O_3 doping on the sensing performance of ZnO porous nanosolid thick film gas sensors

以ZnO纳米粉(平均粒径30 nm)和Fe2O3纳米粉(平均粒径90 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多孔纳米固体厚膜气敏传感器和掺杂Fe2O3(掺杂量为1wt%,2wt%和5wt%)的ZnO厚膜气敏传感器。分别测试了这四种厚膜气敏传感器的本征电阻(传感器在空气中的电阻值)及其对乙醇,汽油,丙酮,对二甲苯,氢气,甲烷和CO敏感特性。结果表明:当工作温度在较低时,Fe2O3的掺杂可明显降低ZnO多孔纳米固体厚膜气敏传感器的本征电阻,并提高其工作稳定性,而适量Fe2O3的掺杂可以提高ZnO多孔纳米固体厚膜气敏传感器对乙醇蒸气和汽油的灵敏度。结合对传感器厚膜的显微结构分析结果,我们对出现上述差异的原因进行了初步讨论。

By using an unique hydrothermal hot -press （HHP） technique, ZnO porous nanosolid and Fe2O3 doped - ZnO porous nanosolids （the content of Fe2O3 is 1 wt %, 2 wt % and 5 wt % respectively） were prepared from ZnO nanopowders （with average particle size of 30 nm） and Fe2O3 nanopowders （with average particle size of 90 nm）. Furthermore, four gas sensors were fabricated using pure ZnO porous nanosolid （denoted as ZFO） and Fe2O3 doped -ZnO porous nanosolids （denoted as ZF1, ZF2 and ZF5 respectively）. The intrinsic resistances （the resistance of sensor in air） and gas sensing properties to ethanol, petrol, acetone, xylene, hydrogen, methane and carbon monoxide of ZF0, ZF1, ZF2 and ZF5 were tested. The results indicated that the doping of Fe2O3 has obviously lowered the intrinsic resistances of the ZnO nanosolid thick film gas sensors and increased their working stability at nearly lower temperature. At the same time, their sensitivity to ethanol and petrol can be improved by the doping of proper amount of Fe2O3. The reason for the above improvement has been analyzed on the basis of micro - morphology obserrations.