Synthesis and spectroscopic characterization of YPO4 activated with Tb3+ and effect of Bi3+ co-doping on the luminescence properties

Bi3+ acting both as an electron and as a hole trap in La-, Y-, and LuPO4

“…For the TL emission (TLEM) spectra, the samples were first heated to 800 K 3 times to empty all relevant traps and then exposed to gamma ray irradiation from a 60 Co source to an absorbed dose of ~1 kGy. TL emission was recorded at a heating rate of 1 K/s utilizing a UV to VIS spectrometer (Ocean Optics, QE65000) and a NIR spectrometer (Ocean Optics, NIRQ512) with a HR composite grating (300 lines/mm) and an entrance aperture of 100 µm leading to a wavelength resolution of 3.3 nm (fwhm).…”

“…The holes released from Pr 4+ or Tb 4+ recombine with electrons at Bi 2+ yielding Bi 3+ A-band emission. The presence of Pr 3+ and Tb 3+ emission lines is explained because part of the energy of Bi 3+ can be transferred to Pr 3+ or Tb 3+ , generating the 4f-4f emission [59][60][61] . The ET processes are further supported by the decreased decay lifetimes of the Bi 3+ A-band emission in YPO 4 :0.005Bi 3+ ,0.005Pr 3+ or Tb 3+ as shown in Fig.…”

Unravelling the energy transfer mechanism in bismuth co-activation of LaInO3:Sm3+/Ho3+ nanophosphor for color-tunable luminescence

“…27,28 L. I. van Steensel et al showed that LaInO 3 :Bi 3+ is an efficient, blue-emitting photo luminescent material 29 and researchers have reported that on co-doping with Bi 3+ , it acts as an excellent sensitizer to enhance the luminescence of RE ions in a wide variety of hosts. [30][31][32][33][34][35][36][37][38] The emission spectrum of Bi 3+ contains a broad band, whose peak maximum varies from blue to green for different host lattices 39 because the outer 6s 2 electronic congurations of Bi 3+ depend strongly on their environmental conditions, such as covalence, coordination number and site symmetry. [40][41][42] Among the RE ions, Sm 3+ and Ho 3+ are important activators for producing signicant orange-red and green emissions for wide applications in optical displays, remote sensing and medical purposes.…”

White luminescence and energy transfer process in Bi3+,Sm3+ co-doped Ca3Al2O6 phosphors

“…Bi 3+ co-doping has been developed as a valuable approach to enhance the luminescence of RE ions [9][10][11][12][13][14][15][16][17][18][19][20][21]. There are about three type of enhancement effect of Bi 3+ on RE ions luminescence.…”

“…The first one is to change the microstructure of RE ions. It was reported that the substitution of Bi 3+ for Y 3+ caused an increase of the refractive index of the matrix and enhanced Tb 3+ luminescence in YPO 4 :-Bi 3+ ,Tb 3+ [9]. The second one is the formation of Bi 3+ -V 5+ metalmetal charge transfer and the subsequent ET from Bi 3+ -V 5+ charge transfer band to RE ions, such as in YVO 4 :Bi 3+ ,Eu 3+ [12][13][14] and Ca 9 Y(VO 4 ) 7 :Bi 3+ ,Eu 3+ [15] phosphors.…”