An effect of Fe on physical properties of nanostructured NiO thin films for nonlinear optoelectronic applications

Nanostructured NiO thin films are fabricated with various concentrations of Fe through a simple spin-coating route and studied for its possible nonlinear optoelectronic applications. The grown films are of good crystallinity grown along (111) plane with single phase of NiO approved by X-ray analysis. The crystallite size values were calculated and noticed to be reduced from 36 to 8 nm with increasing Fe-doping content. Furthermore, FT-Raman spectroscopy also confirmed single phase. EDX approves the presence of Ni, O and Fe in final films and SEM elemental mapping shows homogeneous doping of Fe throughout the NiO films. AFM topographic study reveals the grain size and roughness varies with increase of Fe contents into NiO. The optical study reveals that the grown films are of high transparency which is about 70-85%. The estimation of various optical parameters was done, and direct energy gap found in 3.60 to 3.64 eV region for 0.0, 1, 2.5 and 5 wt% Fe:NiO films, correspondingly. The nonlinear properties were investigated and the values of chi 1,chi 3, and n2 were found to be improved from 0.16 to 0.54, 1.3x10(-13) to 1.25x10(-11) esu and 2.67x10(-12) to 1.70x10(-10) esu, respectively. The enhancement in linear and nonlinear parameters owing to Fe-doping content makes the fabricated films more useful in optoelectronics.