A Promising Deep Red Phosphor AgLaMo[sub 2]O[sub 8]:Pr[sup 3+] with Blue Excitation for White LED Application

Abstract

A deep red phosphor AgLaMo2normalO8:Pr3+ has been prepared by a conventional solid-state reaction technique. The effects of synthesis temperature and Pr3+ -doped concentration on the luminescent properties and crystal structures of the compound have been investigated. Its excitation wavelength ranging from 440 to 500 nm fits well with the characteristical emission of commercial blue light-emitting diode (LED) chips. The photoluminescence spectra of AgLaMo2normalO8:Pr3+ exhibit deep red emissions, with the strongest emission peak at 649 nm, and show high color purity properties with the color point of (0.685, 0.315). Due to its good excitation and emission performance, the Pr3+ -doped AgLaMo2normalO8 phosphor may be a promising candidate for white LEDs.

Blue excited photoluminescence of Pr doped CaBi2Ta2O9 based ferroelectrics

“…The green emission located at 535 and 548 nm are attributed to the 3 P 1 → 3 H 5 and 3 P 0 → 3 H 5 transitions, respectively [30]. The weak red emission located at ∼598 nm is due to the 1 D 2 → 3 H 4 transition [24,30]. From the PL emission spectra, it can be seen that the emission intensity with Pr concentration reaches its maximum at x = 0.02, and decreases contrarily with Pr increasing, owing to the concentration-quenching effect.…”

“…Previous study showed that for a large amount of Pr ions up to x = 0.15 added in Sr 1−x Pr x Bi 2 Ta 2 O 9 solid solution, the sample can keep pure BLSF crystal structure without second phase [27]. The crystal structure of CaBi 2 Ta 2 O 9 is similar to SrBi 2 Ta 2 O 9 , so it is not strange for Ca 1 peaks around 450, 474 and 492 nm are due to the 3 H 4 → 3 P 2 , 3 H 4 → 3 P 1 and 3 H 4 → 3 P 0 transitions, respectively [22][23][24]. It can be seen from the excitation spectra that a band located at 250-340 nm is relatively low, which is not related to any of the transition in the energy levels of Pr 3+ ions; rather it can only be associated with the electronic transition within the host solid.…”

“…4. When electrons are excited to 3 P 2 levels with 450 nm excitation, they relax nonradiatively to 3 P 1 , 3 P 0 and 1 D 2 states and recombined to lower levels of 3 H 4 , 3 H 5 , 3 H 6 and 3 F 2 , the red emission band centered at 621 nm and 658 nm are attributed to the 3 P 0 → 3 H 6 and 3 P 0 → 3 F 2 transitions, respectively [22][23][24]. The green emission located at 535 and 548 nm are attributed to the 3 P 1 → 3 H 5 and 3 P 0 → 3 H 5 transitions, respectively [30].…”

“…The blue excited phosphors are of great significance in the fields of solid state illuminant applications, which are higher efficiency, more safety and environmental friendliness than traditional incandescent and fluorescent lamps [8,21]. For these purposes, blue-excited phosphor based on Pr 3+ -doped oxide hosts such as BaMoO 4 [22], AgLaMo 2 O 8 [23] and SrAl 2 O 4 [24] have been reported. But these oxide hosts do not exhibit electrically functional properties, which cannot meet the integrated applications, for instance, integrated optical and electrical devices.…”

Chemical compatibility and electrical contact between Ni–Cr–Mo alloy and LaCo0.6Ni0.4O3−δ in intermediate temperature solid oxide fuel cells

“…Therefore, based on the above considerations, the ASR of the oxide scale will not take a significant portion of the measured ASR; and the majority of which may be contributed by the AgLaMo 2 O 8 particles embedded in LCN matrix. It is a luminescent material with a tetragonal scheelite structure [24], the conductivity of which has not been reported in literature; however, judged by its crystal structure, the resistivity of i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 3 7 ( 2 0 1 2 ) 1 7 2 5 3 e1 7 2 5 7 AgLaMo 2 O 8 should be considerably high. It is expected that before the oxide scale was fully developed in the early stage of ASR test, Mo evaporated out from the substrate to form AgLaMo 2 O 8 , resulting in increase in the ASR.…”