Enhanced emission of CaNb2O6 : Sm3+ phosphor by codoping Na+/B3+ and the emission properties

Abstract

A series of CaNb2O6:xSm3+ (0 ≤ x ≤ 10 mol%) and CaNb2O6 : Sm3+, Na+/B3+ phosphors were synthesized by the solid-state reaction method in air. Their crystal structures and luminescence properties were investigated and analysed, respectively. Host CaNb2O6 emitted blue light with excitation 270 nm. CaNb2O6:xSm3+ phosphors showed a systematically varied hue from blue to white by changing Sm3+ ion concentration from 0 to 10 mol% with excitation of 270 nm and their chromaticity coordinates were the regions from (0.1665, 0.1767) to (0.2484, 0.2260). Luminescence properties of CaNb2O6 : Sm3+ phosphor were tuned and improved significantly by codoping B3+ or Na+ ions. Energy transfer between Nb\(_{\mathbf {2}}\textit {O}_{\mathbf {6}}^{\boldsymbol {2-}}\) group and Sm3+ ion was observed and analysed via luminescence properties. The luminous mechanism was explained by energy level scheme and energy transfer process in CaNb2O6 : Sm3+ phosphor. The strong excitation band peaking at ∼407 nm indicated that the CaNb2O6 : Sm3+, Na+/B3+ phosphor has a potential application in white light-emitting diodes based on near-UV LED chip.