The recorded photoelectron spectra were analyzed, using the CasaXPS software package. By quantitative analysis in Casa XPS, the signals originating the thin films could be de-convoluted and the chemical composition could be quantified. Gaussian-Lorentz functions and Shirley background were used to fit the experimental XPS data. Surface morphologies were obtained by a Zeiss Gemini SEM 560 scanning electron microscope (SEM) with an acceleration voltage set to 3 kV, a working distance of ∼3 mm and producing images with the in-lens detector.