ABSTRACT
The topography of the nanomaterials is investigated using scanning probe microscopy, atomic-force microscopy, or scanning tunneling microscopy. Electron microscopy became one of the most important techniques to characterize the material's morphology on the nanometer to atomic scale. Photoluminescence spectroscopy is a very sensitive tool for the investigation of electronic states in the bandgap of semiconductors. Ultraviolet–vis spectroscopy is widely used to quantitatively characterize the nanomaterials. Raman spectroscopy is based on the phenomenon called Raman scattering, named after the Indian scientist Raman who first discovered it in 1928. Optical spectroscopy has been widely used for the characterization of nanomaterials. This technique can be generally categorized into two groups: absorption and emission spectroscopy and vibrational spectroscopy. Fourier transform infrared spectroscopy is one of the most widely used tools for the detection of functional groups in pure compounds and mixtures. Scanning electron microscopy is often combined with energy-dispersive x-ray spectroscopy detector to get the elemental composition of the nanomaterials.
