In this paper, undoped, Al-, and In-doped zinc oxide thin films were deposited. Film growth was performed using the sol–gel technique. The method included (a) preparing homogeneous and stable solutions of zinc acetate 2-hydrate, (b) mixing them with aluminum nitrate and indium acetate in 2-methoxyethanol and 2-aminoethanol solutions with various concentrations, and (c) spin coating them onto transparent glass substrates. After thermal annealing, the films showed a high transparency (80–90%) and good stability. Using typical diagnostic tools, the structural, morphological, optical, and electrical film properties were investigated and linked to the dopant type, and concentrations in view of optoelectronics were investigated.

Nanocomposite NiO:Au thin films, formed by gold nanoparticles embedded in a nickel oxide matrix, have been grown by reactive pulsed laser deposition (R-PLD). Two actively synchronized nanosecond laser sources, a KrF excimer laser (248 nm) and a Nd:YAG laser (355 nm), were used for the simultaneous ablation of nickel and gold targets in oxygen ambient. The morphology, composition, and optical properties of the obtained nanocomposites were investigated and were found to correlate with the concentration of Au nanoparticles. Further, the NiO:Au nanocomposites have been tested as hydrogen sensors. Embedding Au nanoparticles into the NiO film matrix reduced the sensors operating temperature and improved their performance by orders of magnitude.