Reddish-orange color tunable Sm3+ activated Gd3Al5O12 phosphors: Crystallographic and photophysical investigation for lighting applications

Abstract

Reddish-orange color emitting Gd3-xAl5O12:xSm3+ (x = 0.01–0.05) nanophosphors has been synthesized via an ideal, economical, less time consuming and urea assisted gel-combustion method. The structural and optical parameters of the synthesized samples were inspected in details. Crystallographic investigations exposed cubic crystal system having space group Ia-3̅d [230]. The particle size estimated through D. Scherrer's relation (20–32) and Williamson–Hall method (20–44 nm) are in good agreement to each other. The morphological analysis reveals that non-uniform agglomerated almost spherical particles lies in the nano-region (18–35 nm). Under the excitation of 276 nm, emission spectra exhibit three broadband centered at 566, 602 and 652 nm having transitions 4G5/2 → 6HJ (J = 5/2 to 9/2). The main reason behind concentration quenching was dipole-quadruple interaction between neighbouring trivalent samarium ions. At last, admirable luminous performance of the optimized sample (x = 0.03) is revealed through CIE chroma coordinates (0.574, 0.390), color temperature value of 1713.66 K and high color purity (89.78%). These excellent results certified the relevancy of the selected nanophosphors as a propitious candidate for the lighting applications.