Structural, Optical and Electrical Properties of Multilayer Stacks ZnO:Al/Ag/ZnO:Al and ZrO2/Ag/ZrO2

Structural, optical and electrical properties of multilayer stacks ZnO:Al/Ag/ZnO:Al and ZrO2/Ag/ZrO2 are studied. The stacks are deposited on glass substrates without heating by r.f. magnetron sputtering consecutively of ZnO:Al and Ag or ZrO2 and Ag targets, respectively. The properties of the as-deposited and annealed in forming gas atmosphere, at 1800C for 1 h are compared. The structural properties of the stacks are studied by TEM and SEM images and demonstrate semi-continuous granular structure of the Ag films. The Ag nanograins in ZrO2 based stacks have a larger size than in the ZnO based stacks. The spectra of transmittance and reflectance have bands resulting from interband transitions of d-shell electrons of Ag atoms and plasma resonance oscillations of free electrons. The sheet resistance of the as-deposited and annealed stacks is in the range 3.1-8.9 Ω/□ and slightly changes after annealing. The deposited stacks have potential for application as a back reflector in thin film solar cells for improvement of light harvesting and their efficiency.