Modification on upconversion luminescence of Er³⁺-Yb³⁺ co-doped BiOCl semiconductor nanosheets through interaction between nanohost and doping lanthanide

We reported the upconversion luminescence (UCL) properties of Er³⁺-Yb³⁺ co-doped BiOCl semiconductor nanosheets synthesized by hydrothermal method. Under 980nm excitation, the red and green UCL of Er³⁺ ions were observed to be populated by a four and three-photon process in the case of absent or low concentration Yb³⁺ dopant. However, an increase of Yb³⁺ dopants show a completely opposite effect on the emission intensity of red and green one, accompanying with the change of upconverting process. It indicates that the red-shifting absorption edge of semiconductor and the super saturation UC processes involved with Yb³⁺ and Er³⁺ doping in BiOCl semiconductor nanosheets, respectively, are mainly responsible for the above UC phenomena.