LaPO4:Ce,Tb and YVO4:Eu nanophosphors: Luminescence studies in the vacuum ultraviolet spectral range

Comparative analysis of the luminescent properties of nanocrystalline LaPO4:Ce,Tb and YVO4:Eu luminescent materials with macrocrystalline analogues, commercially produced by Philips, has been performed under excitation by pulsed vacuum ultraviolet (VUV) synchrotron radiation, ranging from 3.7-40 eV. Special attention was paid to VUV spectral range, which is not reachable with commonly used lamp and laser sources. Our results clearly show distinct difference in the excitation spectra for nano- and macrocrystalline samples, especially at energies, when the spatial separation of electron-hole pairs is comparable with sizes of nanoparticles. Differences in the region of multiplication of the electronic excitations are also demonstrated and discussed.