Studies on the physical properties of TiO2:Nb/Ag/TiO2:Nb and NiO/Ag/NiO three-layer structures on glass and plastic substrates as transparent conductive electrodes for solar cells

Abstract

In this paper, the physical properties of a new series of multilayer structures of oxide/metal/ oxide type deposited on glass and plastic substrates were studied in the context of their use as transparent conductive layers for solar cells. The optical properties of TiO2 /Ag/TiO2, TiO2:Nb/Ag/TiO2:Nb and NiO/Ag/NiO tri-layers were investigated by spectrophotometry and ellipsometry. Optimized ellipsometric modeling was employed in order to correlate the optical and electrical properties with the ones obtained by direct measurements. The wetting surface properties of single layers (TiO2, TiO2:Nb and NiO) and tri-layers (TiO2 /Ag/TiO2 TiO2:Nb/Ag/TiO2:Nb and NiO/Ag/NiO) were also studied and good correlations were obtained with their morphological properties.