四针状ZnO晶须(T-ZnO)的掺杂及其气敏特性研究

采用高温固溶工艺制备了Al3+,Fe3+和Ag+掺杂的T-ZnO气敏材料,并制作了烧结型厚膜气敏元件,测试了元件对H2S,NH3,C2H5OH和H2的敏感特性,研究了掺杂剂、掺杂工艺和材料形貌结构对T-ZnO材料气敏特性的影响规律。结果显示,T-ZnO材料对H2S和C2H5OH气体灵敏度较高,对H2和NH3等气体灵敏度较差;经过H2气氛热处理,掺物质的量百分数为0.1%Al3+的T-ZnO对气体表现出很高的灵敏度,在268.5℃时,对体积分数为10-4的H2S的灵敏度达160;同时,Al3+掺杂工艺改善了材料对H2S和C2H5OH的恢复-响应特性。在Fe3+掺杂ZnO样品中,出现第二相(ZnFe2O4)可以提高对气体的灵敏度。

Study of the Doping of T-ZnO and Its Gas Sensitivity Behaviors

The gas sensors were prepared by T-ZnO doped with Al3+,Fe3+,Ag+ and the gas sensing properties to different concentrations of hydrogen,ammonia,alcohol,and hydrogen sulfide gases were measured.The effects of doping,morphology and structure of the material on the gas sensing properties were also discussed.The results show that the T-ZnO material has more notable gas sensitivity to the alcohol and hydrogen sulfide gases than that to hydrogen and ammonia gases.And the Al doped samples,which show a maximum sensitivity of 160 towards 10-4 of hydrogen sulfide at work temperature of 268.5 ℃,have a better sensitivity than other samples.The response-recovery characteristics of the sensors for H2S can be improved by introducing Al3+ in the lattice of ZnO.