Emerging green light emission of Er³⁺ -activated single phased GdAlO₃ phosphors for lighting applications

An erbium ion (Er³⁺ )-activated gadolinium aluminate (GdAlO₃ ) nanophosphor was synthesized by utilizing urea assisted gel-combustion method. The crystal structure along with all other crystal parameters was determined by X-ray diffraction (XRD) patterns. The selected samples are of orthorhombic phase with Pnma space group. The agglomerated particles within nanorange have been confirmed by transmission electron microscopy (TEM) micrographs. Elemental investigation was performed by energy dispersive X-ray spectroscopy (EDX). Photoluminescence excitation (PLE) spectrum reveals a strong excitation band corresponding to the gadolinium ion (Gd³⁺ ) (276 nm) and a band near ultraviolet (UV) absorption for Er³⁺ (377 nm). Strong excitation band of Gd³⁺ was evident for the energy transfer between Gd³⁺ and Er³⁺ ions. All the doped sampled are excited at 377 nm wavelength. The photoluminescence (PL) spectrum exhibits an intense band at 546 nm (⁴ S_3/2  → ⁴ I_15/2 ) which is responsible for the green emission in the processed samples. The color coordinate values define their color in the green region and correlated color temperature (CCT) values affirm their utility as a cold light source.