The comprehensive characterization of structure, morphology, physical properties of graphene while setting the main focus on qualitative and quantitative defects/disorder studies is crucial for graphene layers evaluation and development acceleration of various graphene applications. In the dissertation work the correlation between the results of distinct analysis methods such as Raman scattering spectroscopy, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, fluorescence and transient absorption spectroscopy (TAS) of graphene of two different structures: the planar graphene and vertical graphene nanosheets (VGN) produced by microwave plasma activated chemical vapour deposition technique has been explored. As most informative and advanced Raman scattering spectroscopy method showed having some limitations, in current research was demonstrated that TAS analysis of the excited state relaxation dynamics in graphene (by measuring hot electrons cooling dynamics that originates from electron-phonon interactions, leading to phonon-phonon interactions) could be a perspective complementary tool as a source of information about the structure, defects and respectively – the quality of graphene. Synthesized planar graphene layers were applied as transparent, flexible electrodes in organic devices.