Reflectivity and abnormal absorption at ITO/Al interface

The electrical and optical thermal stability of indium tin oxide (ITO)/Al bilayers are investigated in this study. The electrical resistivity of ITO and ITO/Al multilayers, both about 1 × 10 ^-3 Ω cm after annealing at 300°C for 1 min, are measured by the four-probe measurement method. In addition to the electrical measurements, we also observe the rapid initial diffusion of Al atoms into the ITO thin films. When the diffusing elemental Al atoms occupy interstitial sites they tend to form defects, causing a serious decrease in the reflectance of the a-ITO/Al bilayer in the wavelength region from 400 nm to 600 nm.