Publication

Abstract : Influence of K+ ion concentrations on the upconversion emissions of LiYF4: Yb, Er phosphor has been investigated. Li1−xKxY0.77F4:Yb0.2, Er0.03 phosphors are synthesized by solid-state reaction method under reduced atmosphere. X-ray diffraction analysis revealed a major phase transition from tetragonal LiYF4 to hexagonal KYF4 as the concentration of K+ ion increases. Blue, green and red upconversion emissions are observed when the samples are excited at 980 nm. Green and red luminescence intensities are affected by the inclusion of K+ ion concentrations in the host lattice. Downshifting photoluminescence and the corresponding decay analysis are carried out for the Li1−xKxY0.77F4:Yb0.2, Er0.03 phosphors under the excitation wavelength of 378 nm. Significant changes in the emission intensity of the green to red ratio suggest the tuning of the emission color with the modification of the K+ ion concentrations in Li1−xKxY0.77F4:Yb0.2, Er0.03 host and such successful tuning in the color of emission can find potential applications in the field of display devices.