Multi-wavelength images detector for micro-cathodoluminescence analysis

Abstract

A novel instrument capable of collecting the entire cathodoluminescence emission spectrum simultaneously with SEM scanning is presented in this work. The cathodoluminescence produced in a standard scanning electron microscope is collected and analyzed. The electronic signal used by the microscope to trigger the electron raster and produce an image is also used by the spectrograph to synchronize spectrum acquisition. At each point in the sample the complete spectrum is acquired. All the data are recorded and saved in an electronic file. With this information it is possible to reconstruct panchromatic and/or monochromatic images of the sample and correlate its optical properties with its microstructure. Instead of an elliptical mirror to collect the light in the conventional CL system, a single optical fiber is used. This new way of acquiring light permits a reduction in the work distance (down to 5 mm) in the microscope, thus achieving a better spatial resolution. Another advantage of this arrangement is that we can simultaneously use other detection modes such as backscattered electrons, x-rays etc. Examples showed here illustrate the capabilities of the instrument.