Enhanced emission of CaNbO : Sm phosphor by codoping Na/B and the emission properties.

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