Sm3+-activated YAG nanocrystals: Synthesis, structural and spectroscopic analysis for orange-red emitting LEDs

Abstract

Trivalent samarium (Sm3+)-activated Y3Al5O12 (YAG) nanocrystals have been successfully synthesized via solution combustion route due to their potential luminescent applications. The samples were synthesized at 600 °C using urea as a fuel and calcined at 950 and 1050 °C for further analysis. X-ray diffraction (XRD), Fourier transformation infrared (FTIR), transmission electron microscope (TEM), energy dispersive X-ray (EDX) and photoluminescence (PL) studies were employed to analyze the materials. The diffraction patterns of as-prepared YAG and YAG:Sm3+ samples were consistent with JCPDS card No. 73-1370 with cubic unit cell and Ia3¯d space group. Rietveld refinement analysis employed to determine unit cell dimensions and lattice parameters also confirmed a predominant cubic phase for both the lattices. The homogeneously disseminated nanocrystals with smooth morphology and particle size of 35−60 nm were observed for as-prepared YAG:Sm3+. EDX analysis proposed the pure synthesis of materials with presence of elements integrated within host lattice. Y3Al5O12:Sm3+ phosphors yielded bright emission in orange-red region owing to 4G5/2→6H7/2 (605 nm) electric dipole transition under 405 nm excitation. Critical distance confirmed that the energy transfer occurs via multipolar interaction mechanism. The luminescence and structural investigations support the convenient utility of Y3Al5O12:Sm3+ materials in solid-state lighting and other optoelectronic devices. All the results suggest that Sm3+-activated YAG nanocrystals have extensive potential applications in near UV-LED or white light sources.