Abstract
Mn2+ and the trivalent europium (Eu3+)-doped MgGa2O4 ceramics are characterized using a multi-experimental approach. The formation of spinel-structured ceramics is ascertained from X-ray diffraction (XRD) analysis. Morphology investigations with transmission electron microscopy (TEM) show irregularly shaped grains and grain boundaries with a homogeneous distribution of Eu3+ ions. The inability of Eu activator to penetrate the bulk of ceramic grains is inferred from positron annihilation lifetime spectroscopy data. The Eu doping is shown to enhance the positron trapping rate due to the occupancy of vacancy-type defects at ceramic grains by Eu3+ ions. Both Mn2+ and Eu3+ doped samples show a broad multi-color luminescence in 350–650 nm range under 240 nm and 270–300 nm excitations. Blue emission is concluded to originate from host defects, whereas green emission and narrow lines in the red region of the spectrum are attributed to Mn2+ and Eu3+ ions, respectively. High asymmetry around Eu3+ ions can be concluded from the photoluminescence and positron annihilation lifetime spectra analysis.
Highlights
Flat-panel displays have drawn much interest recentlyJ Adv Ceram 2020, 9(4): 432–443 comprising an archetypal research challenge in nowadays optoelectronics [1,2,3,4,5]
The Rietveld refinement analysis of X-ray diffraction (XRD) patterns confirms the existence of the spinel phase in the structure of magnesium gallate MgGa2O4:Mn2+ ceramics, whereas Eu-doped MgGa2O4:Mn2+ ceramics show a small amount of Eu3Ga5O12 phase
The homogeneous distribution of Eu dopants is proven by transmission electron microscopy (TEM)–energy-dispersive X-ray spectroscopy (EDS) mapping
Summary
Flat-panel displays (plasma, field-emission, electroluminescence, etc.) have drawn much interest recently. The 380 nm pumping radiation obtained from conventional ZnO electroluminescence or ultraviolet light-emitting diode (UV-LED) technology was used for the excitation of phosphors in flat-panel display systems. The PL of MgGa2O4 ceramics doped with Eu3+ has been studied in Refs. The combination of orange PL associated with Eu3+ dopants with blue intrinsic PL of host lattice and green PL of Mn2+ ions makes it possible to obtain phosphors in the visible range of spectrum using spinel-type compounds alone [8,9]. Spinel-structured non-transparent MgGa2O4 ceramic phosphors prepared by solid-state reactions and doped with Mn2+ and Eu3+ activators are comprehensively characterized with X-ray diffraction (XRD), scanning transmission electron microscopy (STEM) with energy-dispersive X-ray spectroscopy (EDS) analysis, positron annihilation lifetime (PAL) spectroscopy, and photoluminescent (PL) methods. The use of a multi-experimental approach allowed us to shed more light on the correlation between PL mechanism and preferential surroundings of Eu3+ activators in these ceramic phosphors
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
