Colour tuning and energy transfer pathways in MgAl2O4 triply doped with 0.1% Ce3+, 0.1% Eu2+, x% Tb3+(0⩽x⩽2%) nanocrystals synthesized using sol-gel process

A series of the undoped, 0.1% Ce3+, 0.1% Eu2+, 0.1% Tb3+ singly doped and 0.1% Ce3+, 0.1% Eu2+, x% Tb3+ (0⩽x⩽2%) triply doped MgAl2O4 nanophosphors were synthesized by the sol-gel technique and thereafter annealed at 800 °C. The nanocrystals consist of the pure cubic structures. The type of the dopant and varying the Tb3+ mol% influence the crystallites size and morphology of the prepared powders. Photoluminescence (PL) results showed a red emission from Ce3+ singly doped MgAl2O4. Furthermore, the PL results revealed the existence of the energy transfer from Eu2+ → Tb3+ → Ce3+. CIE colour chromaticity showed that the colour can be tuned from bluish → greenish by changing the Tb3+ mol% and the excitation wavelength.