Luminescence of Co-doped SrTiO_3:Pr~(3+)

The SrTiO3∶Pr3+ material,co-doped with monovalent Li+,divalent Mg2+,and trivalent Al3+ was prepared by a new sol-gel method. The phase and crystallinity of the synthesized materials were investigated by powder X-ray diffraction(XRD) and scanning electron microcopy(SEM). Among the co-doped ion,Al3+ incorporation caused the least lattice change and had the best crystallinity. Photoluminescence spectra were taken to investigate the luminescence characteristics. We observed a red luminescence change of SrTiO3∶Pr3+ after being co-doped,and a best enhancement on the red luminescence with the trivalent Al3+ was observed. The present results indicated that the charge defect associated with Al3+ has led to charge compensation of Pr+Sr and also implied that the charge defects(usually the second dopant ions replacing the A or B sites in the lattice) which are closer to Pr+Sr contribute more to the red luminescence enhancement.