Effect of Cr~(3+)-doping concentration on luminous intensity of Zn_(1.4)Al_(1.2)Ge_(0.4)O_4:xCr~(3+)

摘要

Zn_(1.4)Al_(1.2)Ge_(0.4)O_4:xCr~(3+) (x = 0.1%, 0.25%, 0.5%, 1%, 2%) phosphors were prepared at 1400 °C by conventional solid-state reaction, and their phase compositions and luminescence properties were well characterized by means of XRD, photoluminescence spectra, decay curves and TL techniques. With Cr~(3+) doped Zn_(1.4)Al_(1.2)Ge_(0.4)O_4:xCr~(3+) phosphors exhibited near-infrared emission at 696 nm due to the ~2E→ ~4A_2 transition of Cr~(3+) ions. The experimental results reveal that the Cr~(3+) doping concentration plays the crucial role in the luminescence performance of Zn_(1.4)Al_(1.2)Ge_(0.4)O_4:xCr~(3+) phosphors. When the Cr~(3+) concentration was determined to be 1%, Zn_(1.4)Al_(1.2)Ge_(0.4)O_4:xCr~(3+) phosphors obtained optimal the luminescence and afterglow performance. The mechanism of phosphor has been discussed. And the TL results revealed the depth and concentration of traps in the phosphor will be affected by the Cr~(3+) doping concentration.