Microstructure and optical properties of TiO2 nanocrystallites–CaTiO3:Pr3+ hybrid thick films

Long afterglow CaTiO3:Pr3+ ceramic powders were integrated with hydrothermal TiO2 nanocrystallites via “doctor-blade” and TiO2-CaTiO3:Pr3+ hybrid thick films on FTO substrate were fabricated. Effects of the Pr3+ doping level (0.06%, 0.3%) and the CaTiO3:Pr3+/TiO2 weight ratio (0.23, 0.92) on the crystallinity, morphologies, optical transmittance and photoluminescence (PL) properties were investigated. Results showed that the crystallinity of the hybrid films originated from both TiO2 nanocrystallites and CaTiO3:Pr3+ ceramic particles, affected little by the integrating process. The film surface became denser and coarser due to the incorporation of CaTiO3:Pr3+ micron/submicron particles, and the film thickness varied little (∼2.2μm). The optical transmittance of the hybrid film decreased sharply (<20% for 0.92 incorporation level) due to the scattering effects of the CaTiO3:Pr3+ micron/submicron particles to the incident light. All the hybrid films exhibited strong PL at ∼613nm when excited with 332–335nm,...