Wide-band excited and deep-red sensitized Mn 2+ emission from an NaSrSc(BO 3 ) 2 :Eu 2+ ,Mn 2+ phosphor with vanished Eu 2+ emission.

It is of great importance to develop new broadband red phosphors since they have possible applications like plant cultivation, indoor lighting and non-destructive sensing. Herein, we report a series of Eu 2+ , Mn 2+ activated NaSrSc(BO 3 ) 2 phosphors via a conventional solid-state reaction route. It has been found that both Mn 2+ and Eu 2+ solo-doped NaSrSc(BO 3 ) 2 show weak or no luminescence, while Eu 2+ , Mn 2+ co-doped NaSrSc(BO 3 ) 2 exhibits wide-band absorption and intense deep-red emission at 680 nm with color purity of 89%. Analysis of the absorption, excitation and emission spectra of Eu 2+ , Mn 2+ solo- and co-doped NaSrSc(BO 3 ) 2 indicates that this deep-red broadband emission originates from Eu 2+ sensitization of the octahedron Mn 2+ 4 T 1 - 6 A 1 transition. It was found that the photoionization process led by energetic similarity of the host band-gap and the Eu 2+ lowest 5d excited state was mainly responsible for the vanished luminescence of Eu 2+ . The values of internal quantum efficiency (IQE) and absorption efficiency (AE) for the optimal NSSO:0.007Eu 2+ ,0.05Mn 2+ sample are 24.5% and 61.8%, respectively. This work could provide new insights into exploring novel Mn-activated deep-red luminescent materials.