The Bond-Energy Method in Site Occupancy and Property of High Concentration Eu 3+ in Sr₂CeO₄ Phosphors.

The low concentration of Eu3+ doped Sr₂CeO₄ phosphors has been widely studied in recent years and in this paper, we researched the properties of high concentration Eu3+ doped in Sr₂CeO₄. The Sr₂Ce(1- x ) Eu4- x /2 ( x = 0, 1%, 10%, 20%) phosphors were obtained by traditional solid-state reaction. Photoluminescence (PL) spectra are characterized the property of samples. PL spectra illustrate that the concentration of Eu3+ increased, the intensity of 5 D0 -7 F1 , 5 D0 -7 F₂ increased and intensity of Sr₂CeO₄ host emission intensity was decreased. The phenomenon can be ascribed to the energy transfer from Ce4+ to Eu3+ . When the concentration of Eu3+ is 20%, the completely red emission can be obtained even if no other ions are doped under the excitation wavelength of 350 nm, it is proved that Eu3+ occupied Ce sites rather than Sr site in Sr₂CeO₄ samples. The conclusion we make is due to the value of |Δ E Eu Ce-O | and |Δ E Eu Sr-O | calculated by bond-energy method, the smaller the value, the easier it is for the doped ions Eu3+ to enter the site.