Cathodoluminescent images and spectra of single crystals of Y2O2S:Tb3+ and Gd2O2S:Tb3+ nanometer sized phosphor crystals excited in a field emission scanning transmission electron microscope

Cathodoluminescence (CL) spectra have been collected from single nanometer-sized crystals of Y1.98Tb0.02O2S and Gd1.98Tb0.02O2S using a Gatan Vulcan cathodoluminescence imaging spectrometer. Slight variations observed in the CL spectra taken from the crystals are explained, and discussed in relation to bulk samples.