Luminescence and Vacuum Ultraviolet Excitation Spectroscopy of Nanophosphors under Synchrotron Irradiation

Abstract

Vacuum ultraviolet (VUV) excitation spectroscopy under synchrotron irradiation is a powerful tool for the investigation of luminescence properties of wide bandgap nanocrystalline phosphor materials. The advantages of selective excitation in a wide spectral range present the possibility to explore the different aspects of luminescence processes in nanophosphors separately. It is shown that direct excitations of emission centers in wide bandgap materials need excitations in VUV spectral range and such excitations provide valuable information about f–f, f–d transitions, defects, and excitonic transitions in wide bandgap nanophosphors. It is also demonstrated that size‐dependent luminescence properties of nanophosphors are significant if the electron thermalization length becomes larger than the size of the nanoparticles. In this case, multiplication of electronic excitations processes well‐known in bulk materials are suppressed strongly in nanophosphors.