Structural disorder-dependent upconversion in Er3+/Yb3+-doped calcium titanate

In this work, we evaluated the photoluminescence of distinct Er/Yb-doped CaTiO3 powders prepared by the polymeric precursor method, i.e., the crystalline form (structurally ordered) and another form (structurally disordered) before structural order was reached. Upconversion luminescence and photoluminescence are correlated to structural order-disorder. The CT:Er,Yb material presents broad-band emission under UV irradiation and green upconversion luminescence under IR irradiation.