Hello all
I have prepared Zinc Oxide nanoparticles using sol gel synthesis. I tried to coat the ITO and glass substrates with the ZnO nanoparticles ( dispersed in ethanol). But I am not sure if the film has been formed as there is no color change during the annealing of the substrates. How can I visually get an idea that the films have been coated? I am planning to use Zinc Oxide as an ETL in perovskite LEDs.