Figure 11

(a) Partial energy level diagram of Ho³⁺ and Eu³⁺ and energy transfer schematic of CYO:Ho³⁺,Eu³⁺ nanophosphor (b) The Commission International de L’Eclairage (CIE) chromaticity coordinates of CYO:Ho³⁺,xEu³⁺ (0, 1, 3, 5, 7, 9 mol%) nanophosphor sample.