Synthesis and photoluminescence properties of Mn²⁺ doped Ca_1-xSr_xCN₂ phosphors prepared by a carbon nitride based route

Erwan Leysour de Rohello (1) , Yan Suffren (2) , Odile Merdrignac-Conanec (1) , Olivier Guillou (2) , C. Calers (1) , François Cheviré (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 INSA Rennes - Institut National des Sciences Appliquées - Rennes

Mn²⁺ doped Ca_1-xSr_xCN₂ phosphors were synthesized by a solid-state reaction in only 1h under NH₃ atmosphere at 700 °C from doped calcium carbonate and carbon nitride as precursors. The samples were characterized by powder X-ray diffraction, scanning electron microscopy and their diffuse reflectance and luminescence properties were investigated in order to evaluate the potential of such systems as red phosphors. All pure and well-crystallized Mn²⁺ doped samples exhibit broad red emission around 680 nm when excited at 270 nm at room temperature corresponding to the ⁴T_1g (4G) → ⁶A_1g (6S) transition. Maximum emission in CaCN₂:Mn is obtained for Mn²⁺ content of 4%mol and is stable up to 343 K and then shows a 20% decrease at 393 K. Finally, the progressive substitution of Sr²⁺ for Ca²⁺ evidences a solid solution domain between CaCN₂ and β-SrCN₂ with continuous increase of the crystal lattice dimensions. However, such substitution has no impact on the wavelength emission but leads to a decrease of the luminescence efficiency of the phosphor.

Keywords: alkaline-earth; carbodiimide; carbon nitride; luminescence; phosphor

Domains: Chemical Sciences; Material chemistry; Chemical Sciences; Inorganic chemistry

Erwan Leysour de Rohello, Yan Suffren, Odile Merdrignac-Conanec, Olivier Guillou, C. Calers, et al.. Synthesis and photoluminescence properties of Mn²⁺ doped Ca_1-xSr_xCN₂ phosphors prepared by a carbon nitride based route. Journal of Solid State Chemistry, 2021, 300, pp.122240. ⟨10.1016/j.jssc.2021.122240⟩. ⟨hal-03213306⟩