Enhanced electrical stability of flexible indium tin oxide films prepared on stripe SiO2 buffer layer-coated polymer substrates by magnetron sputtering

The electrical stability of flexible indium tin oxide (ITO) films fabricated on stripe SiO2 buffer layer-coated polyethylene terephthalate (PET) substrates by magnetron sputtering was investigated by the bending test. The ITO thin films with stripe SiO2 buffer layer under bending have better electrical stability than those with flat SiO2 buffer layer and without buffer layer. Especially in inward bending text, the ITO thin films with stripe SiO2 buffer layer only have a slight resistance change when the bending radius r is not less than 8 mm, while the resistances of the films with flat SiO2 buffer layer and without buffer layer increase significantly at r = 16 mm with decreasing bending radius. This improvement of electrical stability in bending test is due to the small mismatch factor α in ITO–SiO2, the enhanced interface adhesion and the balance of residual stress. These results indicate that the stripe SiO2 buffer layer is suited to enhance the electrical stability of flexible ITO film under bending.