White light emission from Ca9Bi(PO4)7:Dy3+ single-phase phosphors for light-emitting diodes

A novel single-phase white light emitting phosphor Ca9La(PO4)5(SiO4)F2:Dy3+: synthesis, crystal structure and luminescence properties

“…[16][17][18] Customarily, Dy 3+ ions generate two dominant emissions in blue (475-500 nm) and yellow (570-600 nm) regions, which correspond to 4 F 9/2 / 6 H 15/2 (magnetic dipole transition) and 4 F 9/2 / 6 H 13/2 (electric dipole transition) transitions, respectively. 19 To our knowledge, the electric dipole transitions of Dy 3+ ions can be easily affected by the crystal eld environment of the host lattice rather than the magnetic dipole transitions of Dy 3+ ions. Thus, it is an effective strategy to obtain white light emission in Dy 3+ activated luminescent materials by adjusting the chemical environment of the matrix.…”

Single Phase Cool White Light Emitting Novel Ca9Al(PO4)7: Dy3+ Nanophosphor under NUV excitation

“…In our experimental work, the blue emission peak at 481 nm is stronger than the yellow emission peak at 572 nm for each sample which ultimately confirmed that the dopant Dy 3+ ions are situated at high symmetric sites into the host (Ca9Al(PO4)7) matrix. Table 3 and it is well depicted that Y/B values do not show significant change with the increase in the concentration of Dy 3+ ions, which means dopant ions are located in high symmetrical sites and electric dipole transitions dominate [23].…”

Single phase cool white light emitting novel Ca9Al(PO4)7:Dy3+ nanophosphor under NUV excitation

“…The calculated Y/B values of Ca9DyxAl(1-x)(PO4)7 (x = 0.01 -0.15 mol) phosphors are reported in Table 3 and it is well depicted that Y/B values do not show significant change with the increase in the concentration of Dy 3+ ions, which means dopant ions are located in high symmetrical sites and electric dipole transitions dominate [23].…”

“…For Dy 3+ ions, luminescence peaks are produced in regions blue (470-500 nm) and yellow (570-650 nm) corresponding to the 4 F9/2→ 6 H15/2 and 4 F9/2→ 6 H13/2 transitions respectively. So by regulating the intensity ratio of yellow to blue emission, it is possible to obtain white light from Dy 3+ activated compounds [22,23]. Also, the selection of the host matrix along with activator ions is a matter of consideration.…”

“…But Nowadays, inorganic phosphate compounds A9B(PO4)7 type where ( A = Ca 2+ , Sr 2+ , and B = La 3+ , Y 3+ , Gd 3+ , and Al 3+ ions) have been widely attaining the limelight in the domain luminescent materials due to their rare optical properties, less sintering temperature, low cost of synthesis and high chemical stability, etc. [23,27,28]. Consequently, Ca9Al(PO4)7 could be a good choice as a host matrix for fabricating rare-earth ions doped nanophosphors.…”