Influence of synthesis conditions on optical and electrical properties of CaTiO3:Pr3+ thin films deposited by radiofrequency sputtering for electroluminescent device

CaTiO3:Pr3+ is a phosphor of great interest for electroluminescence application owing to its intense red emission characterized by CIE coordinates very close to those of the NSTC “ideal red”. In this paper, thin films of CaTiO3:Pr3+ are deposited by radiofrequency sputtering technique in pure argon and post-treated by Rapid Thermal Annealing (RTA). The influence of the deposition pressure (0.125-4.5 Pa) and annealing conditions on the optical and electrical properties of the thin films is investigated. The chemical composition of the as-deposited films, checked by Rutherford Backscattering Spectroscopy (RBS), is close to that of the ceramic target used for the deposition. The crystal structure is confirmed to be orthorhombic by X-ray diffraction. We highlight an improvement of the optical and electrical properties of the films after RTA treatment. Moreover, a net gain is obtained by comparison with conventional thermal treatment procedures in classical furnaces, especially for the reduction of electrical defect densities.