Amorphous and Nanocrystalline Magnetron Sputtered CuO Thin Films Deposited on Low Temperature Cofired Ceramics Substrates for Gas Sensor Applications

The cupric oxide (CuO) thin films are promising materials in gas sensor applications. The CuO exhibits the highest sensitivity for hydrogen sulfide, but it may be also used as a sensor for carbon monoxide or nitrogen dioxide. The sensitivity and long-term stability are the critical issues in such applications. The author presents the investigation results on amorphous films of the CuO and nanocrystalline CuO doped with Au, Pd, and Cr. The films have been deposited in magnetron sputtering technology on low temperature cofired ceramics substrates. The results of gas sensors´ response are as well presented and discussed. The long-term stability test has been performed. The films phase composition, microstructure, and surface topography have been assessed by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy methods.