Abstract
Ca2SiO4 phosphors doped with Tb3+ ions have been synthesized by the solid-state reaction method using rice husk and egg shell as the starting raw materials. The prepared Tb3+-doped Ca2SiO4 phosphors exhibited monoclinic structure and the diffraction patterns reveal the single phase of calcium silicate. The emission spectra were measured under the excitation of 369 nm. The spectra show six emission peaks centred at 624, 584, 543, 489, 436 and 414 nm, assigned to the 5D4→7F3, 5D4→7F4, 5D4→7F5, 5D4→7F6, 5D3→7F4 and 5D3→7F5 transitions, correspondingly. With increase of the Tb3+ content from 0.1 to 1.0 mol %, the emission intensities are found to be increased and then decreased after 1.0 mol %. The shortening of lifetime from 2.70 to 2.31 ms was observed with increase in Tb3+ doping content from 0.1 to 2.0 mol % which is ascribed to the cross-relaxation between the 5D3 and 5D4 states in Tb3+. The chromaticity co-ordinates were calculated from the emission spectra and found to be (0.13,0.47), which falls in the exact green region. The results indicate that the low cost Tb3+-doped Ca2SiO4 phosphors are useful for the green component of white light emitting devices.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call