Structure Distortion and Sm 3+ Sensitized Optical Properties of Sr 3 SiO 5 :Eu 2+ for White Light Emitting Dioxide

Abstract

Sr_{2.92 –x} Sm _x SiO₅:0.08Eu²⁺ (x = 0–0.08 mol) phosphors for near-ultraviolet white light-emitting diodes were synthesized via sol–gel method. Sm³⁺ act to enhance the maximum emission of Sr_{2.92 –x} Sm_xSi₅:0.08Eu²⁺, which shows two-peak broad band emission at 466 nm 565 nm under the blue excitation due to the typical electron transition of Eu²⁺ 4f ⁷ → 4f ⁶5d ¹. Moreover, the blue emission disappears and the orange emission reaches the peak value when excitation wavelength increased. Namely, Eu²⁺ is located at two different crystallographic sites in the Sr₃SiO₅, under the different excitation wavelengths, the environment and absorption of two sites under the different excitation wavelengths was disparity lead to the different sensitivity for excited light and the energy transfer takes place between the Sm and Eu activators, we proposed the underlying mechanisms of changes in the photoluminescence properties by structure distortion analysis and energy transfer.