Characterization of sol-gel derived scintillating LuBO3 films doped with rare earth ions

Rare earth doped LuBO3 thin films have been prepared by combining sol-gel process and coating techniques such as spin coating and spray pyrolysis. Annealing treatment results in the crystallization of the film as vaterite phase and incorporation of the doping ions in solid solution. XPS and RBS spectroscopies showed that the composition of the films is close to the nominal one. Adventitious carbon has been observed and attributed to incomplete pyrolysis of metal-organic precursors. XPS concentration profiles show a good homogeneity for the films. RBS demonstrated some inter-diffusion between amorphous carbon substrate and borate films resulting in a gradient of carbon at the interface between the substrate and the film itself. Finally scintillation spectra have been recorded and demonstrate the potentiality of these films to be used as X-ray intensifying screens.