Unravelling the energy transfer mechanism in bismuth co-activation of LaInO3:Sm3+/Ho3+ nanophosphor for color-tunable luminescence

Abstract

A series of single-phased and color tunable LaInO₃:Bi³⁺,Ho³⁺/Sm³⁺ nano phosphors were synthesized via a cost effective and low temperature chemical route. The crystal structure, morphology, photoluminescence (PL) and energy transfer mechanism between Bi³⁺ to Ho^3+/Sm³⁺ were investigated in detail. The considerable spectral overlap between the broad emission band of Bi³⁺ around 400–500 nm and the excitation band of Ho³⁺ and Sm³⁺ supports the efficient energy transfer from Bi³⁺ to Ho³⁺/Sm³⁺, which enhances the PL intensity remarkably. The energy transfer efficiency between Bi³⁺ and Ho³⁺/Sm³⁺ in LaInO₃ was also calculated and the efficiency increased linearly with increasing concentration of Ho³⁺ and Sm³⁺. The emission hue can be tuned from blue to green and pink by varying the content of Ho³⁺/Sm³⁺. This investigation will extend an understanding of interactions between Bi³⁺ and rare earth ions in semiconducting host LaInO₃ and show the potential applications of Bi³⁺, Ho³⁺/Sm³⁺ co-doped nanophosphors in displays and light emitting diodes.