Influence of Pr Doping on the Structural, Morphological, Optical, Luminescent and Non-linear Optical Properties of RF-Sputtered ZnO Films

The effects of Pr doping on the structural, morphological, optical and non-linear optical properties have been investigated. X-ray diffraction and Raman analysis reveals the formation of highly c-axis-oriented films with hexagonal wurtzite structure of ZnO. Atomic force microscopy and scanning electron microscopy images reveal the formation of grains with well-defined grain boundaries. The Pr-doped films present excellent optical transparency in the visible region. The photoluminescence spectra show both UV and visible emissions and the intensity of the visible emission increases with Pr doping. Nonlinear optical properties of the Pr-incorporated ZnO nanostructures have been investigated using the open aperture Z-scan technique. It is interesting to note that 1 wt.% praseodymium-incorporated ZnO film shows saturable absorption, whereas the 5 wt.% praseodymium-incorporated ZnO shows reverse saturable absorption and the high value of non-linear absorption coefficient (β) for 5 wt.% Pr-doped ZnO film suggests the suitability of these films for optoelectronic device applications.