Abstract
Optical materials composed of La1-p-qBipEuqO0.65F1.7 (p = 0.001–0.05, q = 0–0.1) were prepared via a solid-state reaction using La(Bi,Eu)2O3 and NH4F precursors at 1050 °C for two hours. X-ray diffraction patterns of the phosphors were obtained permitting the calculation of unit-cell parameters. The two La3+ cation sites were clearly distinguished by exploiting the photoluminescence excitation and emission spectra through Bi3+ and Eu3+ transitions in the non-stoichiometric host lattice. Energy transfer from Bi3+ to Eu3+ upon excitation with 286 nm radiation and its mechanism in the Bi3+- and Eu3+-doped host structures is discussed. The desired Commission Internationale de l’Eclairage values, including emissions in blue-green, white, and red wavelength regions, were obtained from the Bi3+- and Eu3+-doped LaO0.65F1.7 phosphors.
Highlights
Ce3+ -doped Y3 Al5 O12 (YAG) yellow phosphors are commonly used with blue light-emitting diodes (LEDs) to create white light sources [1,2,3,4,5]
The Ce3+ ions emit in the blue to yellow wavelength regions assigned by 5d1 to 4f1 transitions when excited by ultraviolet (UV) to visible radiation in various host lattices [6,7,8,9]
Like Ce3+ ions, Bi3+ ions act as sensitizers to enhance the anticipated emission light from acceptors, such as Eu3+ or Tb3+ ions in host structures, by facilitating efficient energy transfer [22,23,24,25,26]
Summary
Ce3+ -doped Y3 Al5 O12 (YAG) yellow phosphors are commonly used with blue light-emitting diodes (LEDs) to create white light sources [1,2,3,4,5]. The Ce3+ ions emit in the blue to yellow wavelength regions assigned by 5d1 to 4f1 transitions when excited by ultraviolet (UV) to visible radiation in various host lattices [6,7,8,9]. The Bi3+ ion is an active luminescent center emitting blue to green light assigned to 6s1 6p1 to 6s2 transitions when excited by UV to near UV wavelength regions in host lattices [19,20,21]. The up-conversion properties of Er3+ - and Yb3+ -doped LaO0.65 F1.7 compounds were exploited under 980 nm diode laser excitation in a previous study [27]. Commission Internationale de l’Eclairage (CIE) chromaticity coordinates of the phosphors were structure. Internationale de l’Eclairage (CIE) chromaticity coordinates of the phosphors were obtained
Sign-in/Register to view highlights & summary 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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
