Luminescence study of Sm³⁺,Eu³⁺‐doped Y₂Zr₂O₇ host: optical investigation of greenish yellow to red colour tunable pyrochlore phosphor

Abstract

Pyrochlore phosphors have shown their worth in modern day lighting in the last few years. Colour tunability of the phosphor is one of the modern techniques used to obtain white light‐emitting diodes (WLEDs). In the proposed work, Y2Zr2O7:Sm3+,Eu3+ phosphors were investigated for WLED applications as well as display devices. A convectional solid‐state diffusion method was used to synthesize the proposed phosphors. X‐ray diffraction of the proposed phosphors was performed and compared with the standard Inorganic Crystal Structure Database. The crystal structure of the sample was cubic in nature, obtained from Rietveld refinement. Vibrational and morphological studies on the samples were carried out using Fourier transform infrared spectroscopy and scanning electron microscopy analysis. The photoluminescence study of the colour tunable phosphor showed the characteristic peak of Sm3+ together with the two sharp peaks of Eu3+ ions. Greenish yellow to red colour tunability was observed in the proposed phosphor with enhancement of Eu3+ ions. All these results showed the worth of this sample for WLEDs applications as well as in display devices.

Tailored efficient energy transfer Tb3+, Eu3+activated/co-activated LiAl(PO3)4phosphor by substitution of alkali metals: the effect of charge compensation

“…The microscopic size of the prepared phosphor makes it a potential phosphor candidate as per the point of view of WLED. 53,55,56…”

“…The reason behind the concentration quenching effect observed in the PL emission intensity of the rare earth ion-activated LiAl(PO 3 ) 4 phosphor is the critical transfer distance ( R C ), which is the minimum distance between the nearest activator at a critical concentration X C . The critical transfer distance can be calculated using Blasse formula; 65–67 where, V (=916.439 Å 3 ) is the volume of the unit cell, X C = 1 mol%, and N = 4 number of cationic sites in the unit cell. The value of R C for both rare earth ion-activated LiAl(PO 3 ) 4 phosphors was found to be 35.244.…”

“…The microscopic size of the prepared phosphor makes it a potential phosphor candidate as per the point of view of WLED. 53,55,56 EDS analysis was performed in order to investigate the presence of elements or any other impurities in the prepared phosphor. The EDS analysis of LiAl(PO 3 ) 4 phosphors doped with Tb 3+ /Eu 3+ /M 1+ (M = Na, K) is depicted in Fig.…”

“…The reason behind the concentration quenching effect observed in the PL emission intensity of the rare earth ionactivated LiAl(PO 3 ) 4 phosphor is the critical transfer distance (R C ), which is the minimum distance between the nearest activator at a critical concentration X C . The critical transfer distance can be calculated using Blasse formula; [65][66][67]…”

Tunable warm white light emission and energy transfer of Dy3+ co‐doped Sr2LaZrO5.5:Eu3+ phosphors

“…Sr 2+ is 12‐coordinated point in the crystal and is the centre of the cuboctahedron, which is connected to the surrounding 12O 2− , while La 3+ and Zr 4+ are connected to the surrounding 6O 2− . To maintain the stability of the crystal structure, La 3+ and Zr 4+ are spaced apart and, as charge compensation, oxygen vacancies appear near Zr 4+ [12]. Figure 1 is the XRD diffraction pattern of the matrix Sr 2 LaZrO 5.5 and a series of phosphor samples.…”