Enhancement of Visible Upconversion Emission in Y₂O₃:Er³⁺-Yb³⁺ by Addition of Thiourea and LiOH in the Phosphor Synthesis

Table 1

Crystallite size, lattice parameters, and cell volume for samples prepared with different precipitant agents.

Precipitant agent	Crystallite size (nm)	Lattice parameters (Å)	Cell volume (Å)^3
Thiourea-LiOH	41.5	= 10.582	1184.95
Urea-LiOH	41	= 10.572	1181.60
LiOH	39.5	= 10.608	1193.71
Urea	32.5	= 10.526	1166.25