Growth and Characterization of (Tb,Yb) Co-Doping Sprayed ZnO Thin Films

Structural, optical and electrical properties of (ytterbium/terbium) co-doped ZnO thin films deposited on glass substrates using the spray pyrolysis method were investigated. The films exhibited the hexagonal wurtzite structure with a preferential orientation along (002) direction. No secondary phase was observed in the X-ray diffraction detection limit. Atomic force microscopy (AFM) was performed and root means square roughness (RMS) of our samples decreased with terbium content. Photoluminescence measurements showed a luminescence band at 980 nm which is characteristic of Yb3+ transition between the electronic levels F-2(5/2) to F-2(7/2). This is experimental evidence for an efficient energy transfer from the ZnO matrix to Yb. Hall Effect measurements gave a low electrical resistivity value around 6.0 x 10(-3) omega.cm. Such characteristics make these films of interest to photovoltaic devices.