Synthesis and characterization of new red phosphors for white LED applications

Abstract

An efficient red phosphor, BaMoO 4 :Pr 3+ , has been fabricated by a convenient solid-state method. A strong red emission centered at 643 nm corresponding to the 3 P 0 / 3 F 2 transition of Pr 3+ is observed under 430-500 nm excitation. In addition, improvement of the intensity of the red emission has been achieved by adding an alkali chloride to the BaMoO 4 :Pr 3+ phosphor samples, this being explained by a charge compensation mechanism. The influence of the sintering temperature on the luminescence properties of the phosphors is also discussed.

Enhanced luminous efficiency in Pr3+ activated Ca0.5La(MoO4)2 red phosphor with blue excitation for WLED applications

“…12 it is noticed that the PL intensity increases by the addition of alkali metal chlorides in the following order LiCl, KCl, NaCl compared to a phosphor with no charge compensator. The enhancement in red emission can be attributed to charge compensation effect and explained as follows [43]. Probably, Ca 2?…”

“…For example, the doping of alkali chlorides in BaMoO 4 :Pr 3? phosphor significantly increases the PL intensity [43]. Furthermore, doping of fluoride ions (F -) in LiEuM 2 O 8 (M = Mo, W) greatly reduces the phonon energy of the host lattice and thereby increases the emission property which was analyzed by Wanget al [44].…”

“…possibly occupies the Ca 2? site, will produce a negative-charge defect (M Ca -), which efficiently counterbalance the impact of lessening the luminescence caused by the Pr La defects [43]. The doping of Na ?…”

“…From Fig. 2, it is observed that the addition of charge compensators not only act as a flux [42,43], to support the growth of particles and also it makes the surface of the phosphor become smooth which can improve the emission intensity. The charge compensator Li ?…”

Synthesis and optical properties of Pr3+-doped LaMgAl11O19–A novel blue converting yellow phosphor for white light emitting diodes

“…Since the red phosphor CaTiO 3 :Pr 3 þ was first reported by Diallo [13] lattices. For example, the Gd 2 O 2 S:Pr 3 þ phosphor shows intense luminescence in the green region of the spectrum [14], while BaMoO 4 :Pr 3 þ mainly emits red light [15]. Thus, phosphor materials with excellent luminescence properties can be produced by doping Pr 3 þ ions into suitable host materials.…”