ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Photoluminescence study of combustion synthesis of Sm³⁺ and Dy³⁺ activated MgAl₂O₄ phosphor for w-LEDs

A. N. Yerpude, Roshana T. Maske, Akash S. Padole, Rupesh S. Wandhare, and N. R. Pawar

Department of Physics, N.H. College, Bramhapuri, Chandrapur, India

E-mail: rwandhare1994@gmail.com

Received: 25 April 2025  Accepted: 2 July 2025

Abstract:

A series of Sm³⁺ and Dy³⁺ activated MgAl₂O₄ phosphors was effectively prepared through combustion method. Structural and optical properties are investigated by using XRD, FTIR, and PL analysis. XRD (X-ray diffraction pattern) of prepared sample exhibits that all samples produced are in single phased and match with standard JCPDS no 01-072-1331. The XRD pattern indicates cubic structure. The FTIR spectra of MgAl₂O₄ phosphor show Al–O, Mg–O, and Mg–O–Al stretching vibrations, confirming the MgAl₂O₄ structure. The luminescence properties are comprehensively investigated by recording the photoluminescence (PL) excitation and emission spectra. The MgAl₂O₄:Sm³⁺ phosphors show the strong absorption range in 340–420 nm, which is well suited for the application in LEDs. Under the excitation at 403 nm, the MgAl₂O₄:Sm³⁺ phosphor emits yellow, orange and red emission along the CIE chromaticity coordinates found at 565 nm (0.408, 0.589), 603 nm (0.640, 0.359) and 650 nm (0.725, 0.274). The optimal doping concentration of Sm³⁺ in MgAl₂O₄ was found to be 1 mol%. The photoluminescence (PL) emission spectra of MgAl₂O₄ doped with Dy³⁺ ions exhibit two distinct emission peaks located at 483 nm (⁴F_9/2→⁶H_15/2) and 577 nm (⁴F_9/2→⁶H_13/2). Among these, the 483 nm emission is more intense, indicating a dominant blue emission in the Dy³⁺-doped MgAl₂O₄ phosphor. The measured chromaticity coordinates of MgAl₂O₄: Dy³⁺ phosphor for the emission line at 483 nm and 577 nm were (0.078, 0.170) and (0.492, 0.506), which fall in blue and yellow regions of the CIE diagram, respectively. The concentration mechanism has been studied, and it is caused by dipole–dipole interactions for both Sm³⁺ and Dy³⁺ ions. The results demonstrate MgAl₂O₄:RE³⁺ (RE³⁺ = Sm³⁺, Dy³⁺) phosphors have the potential to function as red–orange phosphors for white LEDs.

Keywords: Aluminate; Rare earth; Sm3+; Combustion technique; W-LEDs

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04235-w

Chemical Papers 79 (10) 6935–6945 (2025)