Efficient dual emission mode of green emitting perovskite BaTiO3: Er3 + phosphors for display and temperature sensing applications

Er3+ ions activated perovskite BaTiO3 green emitting phosphors were synthesized via conventional solid-state reaction method to study the optical spectroscopy and temperature sensing behaviors. Structural analysis based on the X-ray diffraction studies indicates that the phosphors possess the tetragonal structure with space group P4mm (99). The Ba(1-x)TiO3:xEr(3) phosphors exhibited efficient dual emission mode with a sharp and intense visible green emission peaks centred at 525 nm (H-2-(11/2)-> I-4(15/2)) and 550 nm (S-4(3/2)-> I-4(15/2)) via the up-conversion process by using 980 nm Laser source excitation and the down-conversion process upon the 380 nm UV-Light excitation. The fluorescence intensity ratio (FIR) method was employed to analyze the sensing performances of two thermally coupled energy levels (H-2(11/2) and S-4(3/2)) of Er3+ ion in the prepared phosphors. The temperature sensitivity was tested over a wide range of temperature 300-450 K and maximum sensitivity was observed as 0.0032 K-1 at 400 K for optimized stoichiometry Ba(0.3323)TiO3:0.0075Er(3+). Also, the diffuse reflectance spectra were utilized to estimate the optical band gap of Ba(1-x)TiO3:xEr(3+) phosphors are obtained in the range 3.344 - 3.351 eV. Furthermore, the decay time analysis and CIE chromaticity color coordinates were studied in the present work. Therefore, these experimental results indicated the suitability of the Ba(1-x)TiO3:xEr(3+) phosphors for display and temperature sensing applications.