Synthesis and photoluminescence properties of Mn2+ doped ZnCN2 phosphors

Mn2+ doped ZnCN2 phosphors were synthesized by a solid-state reaction from doped zinc oxalate and carbon nitride under NH3 atmosphere at 600 °C in only 1 h. The samples were characterized by powder X-ray diffraction, scanning electron microscopy and their diffuse reflectance and luminescence properties were investigated. All pure and well-crystallized Mn2+ doped samples exhibit broad orange emission around 585 nm when excited at 270 nm at room temperature corresponding to the 4T1g(4G) → 6A1g(6S) transition. Maximum emission is obtained for Mn2+ content of 2 mol% and the emission intensity decreases drastically on the order of 90% between 293 and 385 K. Additionally, the blue luminescence of as-prepared non-doped ZnCN2 is discussed on the basis of the presence of crystal defects.