Cooperative luminescence in ytterbium-doped CsCdBr3

摘要: Abstract Under near infrared excitation, ytterbium-doped CsCdBr3 exhibits a strong blue luminescence due to cooperative effect. The energy level scheme of Yb3+ ions has been determined at low temperature by spectroscopic measurements, allowing us calculate the theoretical spectrum luminescence. good agreement obtained with experimental data confirms process governing anti-Stokes emission. We also present comparison between and rates which is particular interest because trivalent enter this lattice form pairs fixed structure. Theoretical calculations probability are therefore much easier than in other compounds. rate constant 0.13 s−1, whereas dipole-quadrupole forced dipole-dipole interactions result approximately 0.70−1.6 × 10−2s−1 for symmetric 0.76−1.7 10−1s−1 asymmetric ones. From tentative estimation concentration, we find total 2.2 10−2 5.0 10−2s−1. experiment considered be reasonable since radial integrals inserted not adjusted experiment.