Aluminum doped zinc oxide coatings at low temperature by atmospheric pressure plasma jet

Pure and aluminum-doped zinc oxide thin films were produced with an atmospheric pressure plasma (APP) deposition process. Chemical, structural, morphological, electrical and optical analyses were carried out on samples coated with a plasma deposition process and with a spray pyrolysis process for comparison, respectively. The coatings were characterized by a compact layered structure of oxide islands, with a quite uniform distribution of Al in the network. Electrical measurements confirmed the active role and the dispersion of dopant in the zinc oxide network with an observed increase of conductivity even if high resistance values indicated a highly defective microstructure. In comparison to the spray pyrolysis coating the atmospheric pressure plasma coatings show a uniform substrate coverage and a higher chemical purity.