When investigating and developing nanomaterials it is of paramount importance to know exactly what the material is that you are looking at. Spectrometers are the tools that give the composition of things. The science of detecting and analysing compositional data in this way is known as spectroscopy.
How Spectrometers Work
Spectrometers work by analysing energy either absorbed or emitted by a sample of material.
When the sample is stimulated by the input energy source, electrons are excited resulting in the release of energy or photons of light at frequencies uniquely characteristic to particular elements. More powerful intensities correspond to higher concentrations of particular elements.
Figure 1. Typical spectrograph. Each peak corresponds to a particular element.
Types of Spectroscopy
By definition the number of types of spectrometer is limited only by the number of different types of energy source and the name of the form of spectroscopy is normally given by the energy source. Thus Infrared (IR) Spectroscopy analyses light in the IR range, X-Ray Spectroscopy uses X-Rays and UltraViolet-Visible (UV-Vis) Spectroscopy uses light from the visible spectrum including the UV end.
Raman Spectroscopy is also popular in the characterisation of nanomaterials. It is similar to IR Spectroscopy. The difference is that IR Spectroscopy involves detecting what frequencies of IR radiation are absorbed by the sample. Whereas in Raman Spectroscopy, the photon of light emitted after stimulation is what is analysed.