Nature of defects in blue light emitting CaZrO3: spectroscopic and theoretical study

摘要: The optical behaviour of a perovskite ceramic CaZrO3 is investigated. orthorhombic was obtained by gel combustion synthesis which yielded phase pure product at temperatures as low 600°C. Transmission electron microscopy shows the formation highly monodisperse nanospheres calcium zirconate. Despite absence any activator, undoped showed distinct excitation and emission spectra attributed to presence local defects in phase. Photoluminescence decay EPR spectroscopy oxygen vacancies responsible for intense violet blue nanospheres. further confirmed comparing intensity spectrum sample annealed completely reducing oxidizing atmospheres with that prepared sample. To explain PL region, distortion model proposed. Our DFT based hybrid functional calculations show Ca network causes less disorder unit-cell compared Zr network. also comprising complex clusters generates shallow defect states very close valence band maxima leading region.