Highly Efficient Near-IR Photoluminescence of Er3+ Immobilized in Mesoporous SBA-15

Table 1 Comparison of upconversion coefficients in different host materials

Host	N(ions/cm³)	C(×10⁻¹⁸cm³/s)
Yb-Er-SBA-15	2.71 × 10²⁰	0.9–1.1
Phosphate [17]	2 × 10¹⁹-4 × 10²⁰	0.8–1.1
Soda-lime silicate waveguide [17]	1 × 10²⁰	3.8
Er-implanted Al₂O₃ waveguide [17]	1.2 × 10²⁰	4
Alumino-silicate [17]	7 × 10¹⁹-4 × 10²⁰	0.5–2