Lanthanide doped scandia and yttria cathodoluminescent films: a comparative study

A comparative study of red-green-blue cathodoluminescent films based on yttria (Y2O3) and scandia (Sc2O3) as host materials was carried out. Europia (Eu2O3), terbia (Tb2O3) and thulia (Tm2O3) were used as dopant, respectively, for the red, green, and blue light emissions. The films were grown on quartz optical polished substrates heated at 800 degrees C by EB-PVD codeposition. EXAFS and XANES spectroscopies were used for determining the local structure around the lanthanide ion, whereas thin film XRD and HREM were employed to characterize the bulk microstructure. For a given dopant and concentration, the light emissions were found to be more intense for films having scandia as host. This was found to be due to a greater asymmetry of the lanthanide dopant caused by the differences in size between the doping and the host ion.