Nonradiative recombination process in Y2O2S:Eu3+ phosphors

摘要

Abstract: A red cathode-ray phosphor, Y$-2$/O$-2$/S:Eu$+3$PLU$/, shows a large decrease in luminescence efficiency at high excitation density at room temperature. The luminescence intensity is approximately proportional to the square root of the electron-beam current, indicating that a bimolecular-type nonradiative process compares with a radiative process. In undoped Y$-2$/O$-2$/S, broad luminescence bands with peaks at around 355 and 440 nm are found at 80 K. The defect levels involved in this luminescence can be a candidate of the nonradiative process at room temperature, because the luminescence is thermally quenched at room temperature.!6