Table 1 Crystalline Size of La₂O₃, La₂O₃:Tm/Ho, La₂O₃:Tm/Ho,La₂O₃:Ho/Eu, and La₂O₃:Tm/Ho/Eu.

From: Energy transfer and multicolour photoluminescence in phosphors La₂O₃ doped by Tm³⁺, Ho³⁺, and Eu³⁺ for white LED and security applications