Enhanced luminescence properties of Li-doped CaTiO3:Pr3+ thin films grown by PLD under various lithium ion contents

This paper reports the structural and luminescent properties of CaTiO3:Pr3+ and Li-doped CaTiO3:Pr3+ (0.0–5.0 wt.% Li) thin film phosphors deposited on an Al2O3 (0001) substrate using a pulsed laser deposition technique. The structural properties of these films were examined by X-ray diffraction, atomic force microscopy and Fourier transform infrared spectroscopy. The Li+ concentration affected the crystallinity and surface morphology of the CaTiO3:Pr3+ thin films. The crystallinity and emission intensity increased with increasing Li+ content from 0.0 wt.% to 1.0 wt.%. The dominant emission was from the 1D2→3H4 transition at 613 nm. 1D2 emission quenching was also observed in the highly doped sample, which was related to the cross-relaxation process between Pr3+ ions.