Stability/Instability of Conductivity and Work Function Changes of ITO Thin Films, UV-Irradiated in Air or Vacuum. Measurements by the Four-Probe Method and by Kelvin Force Microscopy

This study shows that, after UV-irradiation in air or vacuum, conductivity and work function of ITO and In2O3 come back to their initial values in a few hours or minutes. In addition to this instability, one of the reported drawbacks of ITO is the indium diffusion into the organic layers of operating LED, leading to performance degradation. So, we have reconsidered ITO as transparent anode and explored alternatives such as NiO.