Optical spectroscopy methods for the characterization of sol-gel materials

This paper reviews the main techniques of optical spectroscopy used for the characterization of sol-gel materials in different forms, including a brief description of instrumentation, followed by a series of selected examples from the literature that illustrate the main methodologies and results which can be obtained and including the main advantages and disadvantages of the different approaches adopted. The review includes separate sections on UV/Vis/NIR spectroscopy, spectroscopic ellipsometry, M-line spectroscopy, infrared and Raman spectroscopies, and photoluminescence spectroscopy.