Cathodoluminescence (CL) spectroscopy is useful to determine the wavelength distribution of the emitted light. When the collected light is focused onto the entrance slit of an optical spectrograph or spectrometer, the light is dispersed (separated) by wavelength. Data may be in the form of individual spectra from a few well-chosen points (typically the highest quality spectrum) or spectrum imaging via the collection of a complete spectrum at each point (pixel) of an image. Spectrum imaging requires no a priori knowledge of a specimen and allows the use of advanced analysis techniques.
The spectroscopy workflow is relatively simple, as seen here:
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Locate the region of interest within the sample.
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Set the desired scanning electron microscope (SEM) conditions.
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Ensure the alignment of the CL system to the SEM and sample is correct.
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Define the position of the electron beam.
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Optimize spectrum (optional).
The following pages focus on capturing a spectrum and optimizing the system to maximize spectral information and signal-to-noise ratio. Please follow the links for more information on steps 2 and 3.