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Preparation and Upconversion Emission Properties of Y2O3 : Er, Yb Inverse Opal

Upconversion light-emitting photonic band gap materials (Y<sub>2</sub>O<sub>3</sub>: Yb, Er) with inverse opal structure were prepared by a self-assembly technique in combination with a sol-gel method. The effect of the photonic stop-band on the upconversion luminescence of Er<sup>3+</sup> ions has been investigated in the Y<sub>2</sub>O<sub>3</sub>: Yb, Er inverse opals. Suppression of the upconversion emission was detected if the photonic band-gap overlaps with the Er<sup>3+</sup> ions emission band, while enhancement of the upconversion emission occurs if the emission band appears at the edge of the band gap.