Cathodoluminescence (CL) is the light given off by many materials when excited by an electron beam. It can be collected in the SEM and used to provide important and sometimes unique information about the sample, with SEM resolution.

In geological / earth sciences, colours are meaningful and CL images can be used to distinguish phases which show no contrast different in electron imaging or EDX mapping. In some cases, sensitivity to trace elements is very high.

CL has long been a tool for characterisation of optoelectronic materials and CL images and spectra support material development and device characterisation. CL is also widely applied to other areas of materials science, including ceramics and nanostructures.

In recent years, CL has become a key tool in characterising metal nanostructures, supporting work in plasmonics.

 
CL hardware will be discussed and example data from various materials presented.