Persistent luminescence behavior of materials doped with Eu^2+ and Tb^3+

Abstract

Abstract:In this work, the persistent luminescence mechanisms of Tb 3+ (in CdSiO 3 ) and Eu 2+ (in BaAl 2 O 4 ) based on solid experimental data are compared. The photoluminescence spectroscopy shows the different nature of the inter-and intraconfigurational transitions for Eu 2+ and Tb 3+ , respectively. The electron is the charge carrier in both mechanisms, implying the presence of electron acceptor defects. The preliminary structural analysis shows a free space in CdSiO 3 able to accommodate interstitial oxide ions needed by charge compensation during the initial preparation. The subsequent annealing removes this oxide leaving behind an electron trap. Despite the low band gap energy for CdSiO 3 , determined with synchrotron radiation UV-VUV excitation spectroscopy of Tb 3+ , the persistent luminescence from Tb 3+ is observed only with UV irradiation. The need of high excitation energy is due to the position of 1 and the ligand-to-metal charge-transfer transitions. Finally, the persistent luminescence mechanisms are constructed and, despite the differences, the mechanisms for Tb 3+ and Eu 2+ proved to be rather similar. This similarity confirms the solidity of the interpretation of experimental data for the Eu 2+ doped persistent luminescence materials and encourages the use of similar models for other persistent luminescence materials.

Inorganic lanthanide nanoprobes for background-free luminescent bioassays

“…7a). The excitation energy was firstly accepted by traps and then thermally transferred to Eu 2+ to emit photons lasted for several hours [176].…”

CaTiO3:Eu3+, a potential red long lasting phosphor: Energy migration and characterization of trap level distribution

“…The persistency of the long lasting phosphors (LLPs) and its mechanism have been the subject of intensive research for the last decades due to their versatile applications from commonplace decoration, luminous paints, security illumination and emergency signalization to highly skeptical uses in the detection of high energy radiation, pressure and temperature sensing, micro defect sensing and image storage appliances in different optoelectronics devices [1][2][3]. LLPs are a kind of storage phosphor which can absorb and store energy when it is exposed to high-energy radiation by capturing charge carriers (electrons or holes) in traps (lattice defects or impurities) [4][5].…”

“…For the thermally stimulated storage phosphors the energy is released upon heating based on the principle of thermoluminescence (TL). They have found a lot of industrial applications in the fields of dosimetry, x-ray imaging and as the self-sustained night-vision luminescent materials due to the environmentally friendly nature and economical sustainability [1][2][3][4][5][6][7].…”

“…The mechanisms of the persistent luminescence phenomenon from Eu 2+ based materials have also attracted much attention [1][2][3][4][5][6][7]. But a very little amount of work has been reported on the mechanism of long after glow (LAG) of phosphors using RE 3+ dopants as the LLPs [1] and their relevant applications are challenged by the generation of multicolor LLP using these dopants [1][2][3][4][5][6][7]. Theoretically, multicolor and 3 color tunable LLPs can be obtained by mixing the three primary color-emitting LLPs.…”

Luminescent properties of a green emitting persistent phosphor CdGeO3:Tb3+

“…In addition to sulfides (CaS:Eu 2+ , Tm 3+ , red) [5], oxysulfides (Y 2 O 2 S:Eu 3+ , Ti 4+ , Mg 2+ , red) [6], and nitrides (Ca 2 Si 5 N 8 :Eu 2+ , Tm 3+ , orange) [7], a few orange-red persistent phosphors have been reported such as CaTiO 3 :Tb 3+ [8], Ca 2 SnO4:Sm 3+ [9], and S r3 Al 2 O 5 Cl 2 :Eu 2+ , Tm 3+ [10]. Recently, the advanced persistent phosphors have attracted considerable attention due to the demands for new applications in the medical field such as cancer photodynamic therapy, cancer diagnoses and in vivo imaging except for the traditional domain including emergency signalization, solar energy utilization, image storage, and thermal sensors [11][12][13][14][15][16][17].…”