Design And Performance Of ZnO/NiO Heterostructure Film Ethanol Sensor

In order to be able to accurately detect ethanol gas,we need to use high performance gas sensor.With the continuous progress of materials science,the development of metal oxides has also undergone tremendous changes,it is the current electronic science community has a very important research value of sensitive materials,in which ZnO by electrochemical stability,non-toxic and low prices and become Metal semiconductor oxide gas sensor is very promising a sensitive material,but because of its own gas sensitivity is very low,the experiment we usually need to be its corresponding doping or composite to improve the gas-sensing characteristics.In this paper,it is found that NiO metal oxide is a kind of wide bandgap(4.2eV)P-type semiconductor,with lattice mismatch between ZnO,high hole flow performance,can form ZnO with ZnO Heterojunction.Based on this structure,ZnO / NiO heterostructure films were prepared by sol-gel method,and the corresponding ethanol gas-sensing properties were studied by comparison with the ZnO-NiO composite structure.The results show:The sensitivity of ZnO / NiO heterostructures is up to 43.2,and the maximum sensitivity of ZnO-NiO composite structure is only 27,although the composite structure is higher than that of heterogeneous structure in adapting temperature,but the sensitivity is too low.At the working temperature of 300 ?,the test gas concentration range of 25-300 ppm,the heterogeneous structure and composite structure of ethanol,acetone,hydrogen and methane four kinds of gas selective testing,the ethanol gas sensitivity heterogeneous structure of 36.3,Acetone was 23.4,hydrogen was 19.7,methane was 20.1,and the sensitivity of the composite structure to the four gases was 14.7,5.6,6.3 and 7.0,respectively,which indicated that the selectivity of the heterostructure to ethanol was better than that of the composite structure.After testing,the corresponding and recovery time of the heterostructure was significantly shorter than that of the composite structure and the recovery time was 11 s and 14 s.