Synthesis, characterization, thermo- and photoluminescence properties of Bi3+ co-doped Gd2O3:Eu3+ nanophosphors

Abstract

Gd 2 O 3 :Eu 3+ (4 mol%) co-doped with Bi 3+ (Bi = 0, 1, 3, 5, 7, 9 and 11 mol%) ions were synthesized by a low-temperature solution combustion method. The powders were calcined at 800°C and were characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), Fourier transform infrared and UV-Vis spectroscopy. The PXRD profiles confirm that the calcined products were in monoclinic with little cubic phases. The particle sizes were estimated using Scherrer's method and Williamson-Hall plots and are found to be in the ranges 40-60 nm and 30-80 nm, respectively. The results are in good agreement with TEM results. The photoluminescence spectra of the synthesized phosphors excited with 230 nm show emission peaks at ∼590, 612 and 625 nm, which are due to the transitions 5 D 0 → 7 F 0 , 5 D 0 → 7 F 2 and 5 D 0 → 7 F 3 of Eu 3+ , respectively. It is observed that a significant quenching of Eu 3+ emission was observed under 230 nm excitation when Bi 3+ was co-doped. On the other hand, upon 350 nm excitation, the luminescent intensity of Eu 3+ ions was enhanced by incorporation of Bi 3+ (5 mol%) ions. The introduction of Bi 3+ ions broadened the excitation band of Eu 3+ of which a new strong band occurred ranging from 320 to 380 nm. This has been attributed to the 6s 2 → 6s6p transition of Bi 3+ ions, implying a very efficient energy transfer from Bi 3+ ions to Eu 3+ ions. The gamma radiation response of Gd 2 O 3 :Eu 3+ exhibited a dosimetrically useful glow peak at 380°C. Using thermoluminescence glow peaks, the trap parameters have been evaluated and discussed. The observed emission characteristics and energy transfer indicate that Gd 2 O 3 :Eu 3+ , Bi 3+ phosphors have promising applications in solid-state lighting.

Nd2O3:Gd3+ nanocrystalline phosphor: γ-Induced thermoluminescence, EPR and structural properties

“…anion group. We believe that the possible source of the carbonyl group was from oxalyl dihydrazide fuel used for the combustion synthesis [15].…”

Synthesis and photoluminescence enhancement of the LiLa(MoO4)2:Sm3+ red phosphors by co‐doping with Bi3+

“…The Bi 3+ ions can act a sensitizer to enhance the luminescence intensity of a fluorescent material. [ 20,21,37 ] In this study, the Bi 3+ ions were doped into the LiLa(MoO 4 ) 2 :Sm 3+ phosphors with optimized Sm 3+ dopant levels, and the Bi 3+ doping concentration was varied from 0 to 3 mol%. Figure 7 depicts the excitation spectrum and emission spectra of the LiLa(MoO 4 ) 2 :Sm 3+ ,Bi 3+ phosphors.…”

“…The Bi 3+ ions can act a sensitizer to enhance the luminescence intensity of a fluorescent material. [20,21,37] In this study, the Bi 3+ ions were doped into the LiLa(MoO 4 ) 2 :Sm 3+ phosphors with optimized Sm 3+ dopant levels, and the Bi 3+ doping concentration was varied from 0 to 3 mol%. increasing Bi 3+ dopant concentration, which could be attributed to the Bi 3+ -O 2À charge transfer band and the characteristic absorption band of Bi 3+ ions ( 1 S 0 !…”

Giant Photoluminescence Improvement and Controllable Emission Adjustment in Bi3+-Activated Ca4ZrGe3O12 Phosphors for High-Quality White Light-Emitting Diodes

“…In addition, the electrons in the ground states of Eu 3+ are also excited to 5 D 0 excited energy level in response to n-UV light, then return back to the ground state with the characteristic red emission of Eu 3+ . Therefore, the energy transfer from Bi 3+ to Eu 3+ can achieve color adjustment from blue to red light and enhance the emission intensity of Eu 3+ . , …”

“…Therefore, the energy transfer from Bi 3+ to Eu 3+ can achieve color adjustment from blue to red light and enhance the emission intensity of Eu 3+ . 59,60 Thermal Stability Properties. Thermal stability investigation of phosphors is important for the practical application in pc-WLEDs devices.…”