Synthesis and photoluminescence properties of Sm3+ doped LaOCl phosphor with reddish orange emission and it’s Judd- Ofelt analysis

Abstract

Present paper reports the study on luminescence and optical behaviour of samarium doped lanthanum oxychloride (LaOCl:Sm ^3+ ) nanophosphor for their potentiality in display devices. The conventional solid state route was employed to synthesize the phosphor La _1-x Sm _x OCl (x = 0, 0.01, 0.03, 0.05, 0.07 and 0.09). Tetragonal phase of the prepared compound was confirmed by PXRD. An agglomerated and spherical like structure were seen of the samples from FE-SEM analysis. The Wood and Tauc relation was employed to find out band gap energy and is around 4.23 eV. At an excitation wavelength of 408 nm, a high intense peak of emission was observed at 608 nm for transitions ( ^4 G _5/2 → ^6 H _7/2 ) of Sm ^3+ ions in the PL spectra. Colour co-ordinates (X̄,Ȳ) were used for the analysis of measured photoluminescence spectra. For the optimized concentration of Sm ^3+ (La _1-x Sm _x OCl with x = 0.05), the intensity parameters (Ω _2 , Ω _4 and Ω _6 )were determined. The trend of Ω _6 > Ω _4 > Ω _2 was observed. An emission cross section and Branching ratio are found to be 3.98 × 10 ^−22 cm ^2 and 59% respectively for ^4 G _5/2 → ^6 H _7/2 transition that makes it suitable for laser designs and application. The obtained results reveal that the LaOCl phosphor doped with samarium can be used on the screens of optical electronic systems and also is suitable for emission of reddish orange colour.

Keywords

• rare earth
• oxychloride
• photoluminescence
• Judd-Ofelt