Synthesis, structure and luminescence characteristics of a novel red phosphor NaLa₉(GeO₄)₆O₂:Eu³⁺for light emitting diodes and field emission displays

Abstract

In order to explore a new kind of red phosphor for near ultraviolet white light emitting diodes (NUV-WLEDs) and field emission displays (FEDs), Eu 3+ doped NaLa 9 (GeO 4 ) 6 O 2 was synthesized and its structure and luminescence properties were studied for the first time for fundamental research. The results indicated that they are all crystallized in hexagonal crystal system with the P63/m space group. Eu 3+ doped NaLa 9 (GeO 4 ) 6 O 2 with the content of 0.07 has optimal photoluminescence properties, which had a dominant red emission peak at 612 nm ( 5 D 0 -7 F 2 ) with CIE coordinates of (0.6444, 0.3544) under 392 nm excitation and the quantum efficiency of 45.2%.Additionally, the thermal quenching property has been studied and its possible mechanism has also been expounded. Furthermore, the cathodoluminescence (CL) property was investigated and the result revealed that the sample had excellent degradation property for FEDs. The study reveals that NaLa 9 (GeO 4 ) 6 O 2: 0.07Eu 3+ could be a suitable red-emitting phosphor candidate for NUV-WLEDs and FEDs.

Broad red-emission of Sr3Y2Ge3O12:Eu2+ garnet phosphors under blue excitation for warm WLED applications

“…38,39 The sharp band at 1405 cm À1 can be attributed to the bending mode of O-H bonds. 40,41 It can be also observed that strong absorption bands at 934, 792, and 711 cm À1 are related to the asymmetric vibration of Ge-O bonds. 42 The sharp Fig.…”

“…peaks at 562 and 482 cm À1 represent the characteristic vibration modes of Ge-O-Ge bonds. 40,42 PL properties and quantum yield of SYGO:Eu 2+ phosphors Fig. 3 shows the PL excitation (PLE) and PL emission spectra of the SYGO:0.01Eu 2+ phosphor sample.…”

Nanocrystallization of the Cd3Al2Ge3O12 Garnet in Glasses of the CdO-TeO2-GeO2 System

“…Moreover, the GeO 2 emission is in the UV range and it was discussed previously. [38][39][40]. Chromaticity coordinates of the intrinsic luminescence of cadmium aluminum germanate were estimated (x = 0.3267, y = 0.4795) and are presented in the CIE 1931 color space in Figure 11b, as it can be seen that the emission color is in the yellowish-green region.…”

A novel Eu3+/Eu2+ co-doped MgSrLa8(SiO4)6O2 single-phase white light phosphor for white LEDs

“…7,8 Moreover, trivalent RE (RE 3+ ) ions play an important role in producing highly efficient luminescent materials. [9][10][11][12] Previously reported co-doped white phosphors present several shortcomings in the spectral distribution. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] For the Eu 2+ /Mn 2+ or Ce 3+ /Mn 2+ co-doped systems, the intensity of the peaks are relatively weak in the green region, whereas the Ce 3+ / Eu 2+ or Ce 3+ /Tb 3+ co-doped systems are lack the red component, which will affect the overall luminescent efficiency of materials.…”