Ce³⁺ dopants-induced spectral conversion from green to red in the Yb/Ho: NaLuF₄ self-crystallized nano-glass-ceramics

Yb/Ho: NaLuF₄ self-crystallized glasses were successfully synthesized. After further heat-treatment (forming nano-glass-ceramics), Ho³⁺ upconversion luminescence was enhanced by about 25 times, owing to the increased size and improved crystallinity of cubic NaLuF₄ nanocrystals. Impressively, the introducing of Ce³⁺ dopants into glass ceramics resulted in an increase of red to green emission ratio of Ho³⁺ from ∼0.11 to ∼32 and ultimately induced an intense near-single-band red upconversion luminescence. Such color tunable luminescence was proved to be attributed to the competition of radiation transitions from Ho³⁺⁵S₂,⁵F₄ green-emitting and ⁵F₅ red-emitting intermediate states. - Highlights: • Yb/Ho/Ce: NaLuF₄ embedded bulk glass ceramics were fabricated. • Glass ceramics were achieved by a glass self-crystallized route. • Ce³⁺ dopants induced near-single-band Ho³⁺ red upconversion emission. • Ce³⁺ ↔ Ho³⁺ cross relaxations were responsible for the tunable luminescence.