SEM: Cathodoluminescence

The CL block
Centering the mirror
CL imaging using the SEM
Acquiring spectra
Horiba LabSpec software introduction
CL advice
Acquiring selective waveband images (placeholder)
Acquiring hyperspectral maps (placeholder)

Brochure, software introduction, quick start guide, software manual

Cathodoluminescence is light emission excited by an electron beam. Some materials are intrinsically luminescent, like semiconductors, but most geological and engineering materials are not. However, many materials can be activated (to become fluorescent by several means, including some trace elements (e.g., Mn2+, Fe3+, lanthanides) and a wide variety of crystal defects. Cathodoluminescence is used to study phase growth, growth conditions, defect types, defect density, and other things.

On the left side of the SEM is the Horiba cathodoluminescence spectrometer and imaging system. It has three detectors:

One is photomultiplier PMT1 for imaging using the SEM software (AUX1 detector). It can collect grayscale images using the open filter wheel position. You can also collect images through each of the RGB filters, which can be combined using 3rd party software to produce full color images.

The other two detectors are controlled by the Horiba LabSpec software. PMT2 is a photomultiplier that can make images using specific spectral bands. The other is a cooled CCD array, used for centering the parabolic mirror and collecting spectra.

  • Remove the BSE detector. If you don’t, inserting the mirror will break it.
  • Turn on the SEM and make sure it’s running well. To start, try setting beam voltage and current to 10 keV and 5 nA.
  • Be sure the CL hardware is switched off (red arrow).
  • Turn on (or re-boot) CL computer to the Horiba desktop.
  • Wait at least 30 seconds and switch on the hardware (red arrow).
  • Wait another 30 seconds and start the LabSpec software.

In the SEM system, make sure RemCon32 is communicating with the LabSpec software. If it is, yellow lines of text should periodically scroll up the black RemCon32 window. If it isn’t communicating, be sure the RemCon32 COM port is set to COM4. If that doesn’t work, try COM3. The EDS computer is COM2.