Luminescence characteristics of LiBaBO3:Eu2+ phosphor for white LED

The LiBaBO3:Eu2+ green phosphor was synthesized by high temperature solid-state method. With the Eu2+ doping of 1mol%, the emission and excitation spectra of LiBaBO3:Eu2+ phosphor were measured. The emission spectrum shows two peaks at 482 and 507nm, which are in good agreement with the theoretical values. The excitation spectrum for 482nm emission has two excitation peaks at 287 and 365nm, and for 507nm excitation emission at 365 and 405nm. The effect of Eu2+ concentration on the emission spectrum of LiBaBO3:Eu2+ phosphor was investigated. The results show that red shift takes place in the blue and green emission spectra with increasing Eu2+ concentration, and the blue emission disappears at 3 mol% Eu2+. However, the green emission always exists. The dependence of luminescent intensity of LiBaBO3:Eu2+ phosphor on the Eu2+ concentration was studied, and the results show that the luminescent intensity firstly increases with the increasing Eu2+ concentration, then decreases, and reaches the maximal value at 3 mol% Eu2+. According to the Dexter theory, the concentration quenching mechanism is the d-d interaction.