Enhancement and luminescence properties of Eu3+, Sm3+ co-doped KMgPO4 phosphor with variable concentration of Eu3+ for w-LEDs

This study reports enhancement in emission efficiency of Eu3+ and Sm3+ co-doped KMgPO4 phosphor. The sample was synthesized by a conventional solid-state reaction for the variable concentration of europium. The structural analysis of the sintered phosphor was done by using powder X-ray diffraction, also the photoluminescence behaviour, energy transformation of Sm3+ to Eu3+ and decay properties were studied throughout. It was found that the main intense peak of Sm3+-doped sample reduced when increasing Eu3+ concentration and this shows the energy transfer between Eu3+ and Sm3+ ions, also the decay time of particle get reduced with increasing Eu3+ concentration. So by adjusting the energy transfer between Eu3+ and Sm3+ ions using an optimum concentration of europium ion can improve the emission efficiency and enlarge the excitation spectra and therefore, enhanced the emission efficiency under 402 nm n-UV excitation. This study shows the new methodology for developing the red-emitting phosphor with enhanced emission efficiency. The calculated CIE coordinated for co-doped phosphor was estimated to x = 0.610 and y = 0.381.