Influence of O/Ar ratio on the properties of NiO thin film grown with the method of radio-frequency magnetron sputtering

In order to obtain high quality NiO thin film grown with the radio-frequency magnetron sputtering method, the influence of O/Ar ratio on the structure, band-gap, resistivity and optical transmittance of NiO thin films were studied. It was found that the obtained NiO thin film showed (111) preferred orientation and higher transparency in the visible region. With the increasing of O/Ar ratio from 1∶7 to 8∶2, the optical transmittance of NiO thin films decreased and the optical band-gap was between 3.4.eV and 3.7.eV, and the sheet resistivity decreased from 5.4×107. Ω /□ to 1.0 ×105. Ω /□. Our study shows that the properties of NiO thin films can be adjusted in a wide range by adjusting the O/Ar ratio in the sputtering process.