A Novel Tunable Green- to Yellow-Emitting β-YFS:Ce³⁺ Phosphor for Solid-State Lighting

Abstract

A Ce(3+)-activated fluorosulfide phosphor (β-YFS:Ce(3+)) was synthesized by solid-state reaction in a sealed tube. The crystal structure has been refined from the XRD profiles and there are two different crystallographic rare earth sites, namely, Y(1) and Y(2), where the Ce(3+) ions occupied. The emission band with a maximum at 495 nm of β-Y(0.99)Ce(0.01)FS phosphor was characterized by the 4f-5d transitions of Ce(3+) ion. With increasing Ce(3+) concentration, the emission variations were observed from 495 to 547 nm. When β-YFS:Ce(3+) phosphors were utilized to incorporate with n-UV/blue chip, greenish-white light with color rendering index of 65-77 were obtained. The results indicate that the tunable green- to yellow-emitting β-YFS:Ce(3+) can serve as a potential phosphor for incorporation in fabrication for solid-state lighting. The preparation, spectroscopic characterization, quantum efficiency, thermal-quenching behavior, and related LED device data are also presented.

Recent progress in luminescence tuning of Ce3+and Eu2+-activated phosphors for pc-WLEDs

“…[25][26][27][28][29][30] In general, phosphors are vital to the development of the WLED lighting and backlight display industry. 39,[41][42][43][44][45][46][47] The emphasis was also be placed on the relationships among crystal structures, luminescence properties, and device performances. Therefore, novel and acceptable fluorescent materials for improving the performances of solid-state lighting must be developed.…”

“…[58][59][60][61][62][63][64][65][66][67][68][69] Commonly, the nephelauxetic effect is linked to the covalency of the crystal. [41][42][43][44][45][46][47]93,95 If the activator ions were surrounded by anion groups, the higher charge density on the anion groups would exert the stronger nephelauxetic effect on activator ions. Thus the covalency of the crystal is related to the electronegativity of anions and the cation-anion distance.…”

Tunable photoluminescence properties and energy transfer in oxyapatite-based Ca2Tb8(SiO4)6:Eu3+ phosphors for UV-LEDs

“…White light-emitting diodes (LEDs) have attracted significant attention as potential sources of illumination because of the high brightness, low energy consumption, high reliability, long lifetime and eco-friendliness [1][2][3]. The conventional technique for generating white light is to combine a blue InGaN LED chip with yellow-emitting Y 3 Al 5 O 12 :Ce 3+ (YAG) phosphors [4].…”

Multicolor-emitting Ca3-x-ySry(PO4)2:xEu2+ (0≤x≤0.075, 0≤y≤2.2) phosphors for light-emitting diodes

“…And the most convenient way is coupling yellow emitting Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce) phosphor with blue LED chips [2]. However, this type of white light suffers low color-rendering index (CRI, Ra ~ 75) and high correlated color temperature (CCT ~ 7750 K) due to the deficiency of red emission component [6,7].…”

“…These drawbacks restrict the white LED application in general and medical lighting [7]. To solve this problem, another approach by combining NUV LEDs with a blend of tunable green-to-yellow and red-emitting phosphors has been proposed and paid much attention in recent years [7,8] …”