Microstructure and Characteristics of Thin-Film La0.8Sr0.2Co0.5Ni0.5O3/ZnO:Al Heterocontact CO Sensors Prepared by RF Magnetron Sputtering

作者：Yang Wein Duo^*; Chang Yen Hwei; Huang Chia Chia; Chen Yu Chung

来源：Journal of Electronic Materials, 2009, 38(3): 460-467.

DOI：10.1007/s11664-008-0598-x

• CO gas sensor
• heterocontact
• ZnO:Al/La0.8Sr0.2Co0.5Ni0.5O3
• sputtering

Highly sensitive CO gas sensors based on heterocontacts of ZnO:Al on La0.8Sr0.2Co0.5Ni0.5O3 (LSCNO) were fabricated successfully. La0.8Sr0.2Co0.5Ni0.5O3 thin films were coated on (100) silicon wafers by a sol-gel method including the Pechini process followed by a spin-coating procedure. Then, ZnO:Al films prepared by radiofrequency (RF) magnetron sputtering at various oxygen partial pressures and deposited on as-deposited La0.8Sr0.2Co0.5Ni0.5O3 films were investigated. The results revealed that the CO sensing ability of the film prepared with the ratio of O-2/Ar = 5/5 (ratio of volume flow rate) was the worst, owing to the highest (002) plane orientation in the ZnO:Al film. In contrast, the ZnO:Al film prepared with O-2/Ar = 3/7 exhibited better CO sensitivity. Furthermore, all two-layer samples showed higher CO sensitivities than single-layer samples. The CO sensitivity of ZnO:Al/La0.8Sr0.2Co0.5Ni0.5O3 thin film was 45% for 500 ppm CO at a sensing temperature of 200A degrees C.

• 出版日期2009-3