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Mn-doped ZnO thin films with different percentages of Mn content (0, 1, 3 and 5 at%) and substrate temperature of 350 °C, were deposited by a simple ultrasonic spray pyrolysis method under atmospheric pressure. The chemical compositions and surface morphologies were examined by dispersive x-ray spectroscopy and scanning electron microscopy micrographs. We have studied the structural and optical properties by using x-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy and ultra-violet visible near-infrared spectroscopy. The lattice parameters calculated for the Mn-doped ZnO from XRD pattern were found to be slightly larger than those of the undoped ZnO, which indicate substitution of Mn in the ZnO lattice. Compared with the Raman spectra for ZnO pure films, the Mn-doping effect on the spectra is revealed by the presence of an additional peak about 524 cm−1 due to Mn incorporation. With increasing Mn doping the optical band gap increases indicating the Burstein–Moss effect.

The structure of nanocrystalline silicon thin films (nc-Si:H) deposited by rf magnetron sputtering of a high-purity crystalline silicon target using argon (30%) and hydrogen (70%) gas mixture, under different pressures (P = 2, 3 and 4 Pa) and different substrate temperature (Ts = 100, 150 and 200 °C), has been studied with spectroscopic ellipsometry (SE; 1.5–5 eV) complemented with Raman spectroscopy measurements. The ellipsometry data were carefully analyzed using the Brüggeman effective medium approximation and the Tauc–Lorentz model. The results of this investigation clearly show that the samples deposited at 2 Pa present a completely amorphous structure whatever the substrate temperature, while those deposited at 3 and 4 Pa exhibit a nanocrystalline structure. These results suggest the existence of a threshold pressure around 3 Pa for which crystallization occurs. The samples are well crystallized with a crystalline volume fraction ranging from about 60 to 90%, and exhibit a mixture of small and large crystallite sizes. The deposition temperature has practically no effect on the size of the crystallites and on the average crystalline volume fractions. These results are in good agreement with the Raman spectroscopy data, and suggest the formation of Si crystallites in the gas phase. The analysis of the ellipsometric spectra also shows that the bulk layer is initiated from an amorphous interface (a-Si:H) present in the first steps of the growth, and is followed by a less crystallized subsurface layer.