Cr[sup 3+]-Doped Lanthanum Gallogermanate Phosphors with Long Persistent IR Emission

Lanthanum gallogermanate co-doped with chromium (, where , , , , , and ) samples have been prepared using a solid-state chemical reaction method. The phosphor with is observed to have a persistent IR emission for more than 8 h, which is recorded using a spectrometer. The wavelength of the major IR emission is in the range from 700 to 1100 nm. The intensity of the phosphorescence and persistent time can be modified by co-doping proper trapping centers.