Preparation and upconversion emission properties of TiO2 :Yb, Er inverse opals

Inverse opal photonic crystals of Y b3+, Er3+ co-doped TiO2 (TiO2:Yb, Er) were prepared by a self-assembly technique in combination with a sol–gel method. Upconversion (UC) luminescence properties of the inverse opals were investigated. The results show that photonic bandgap has significant influence on the upconversion emission of the TiO2:Yb, Er inverse opal photonic crystals. Significant suppression of the upconversion emission was detected if the photonic bandgap overlapped with the Er3+ ions emission band.