Optical characterization and defect-induced behavior in ZnAl1.999Ho0.001O4 spinel: Unraveling novel insights into structure, morphology, and spectroscopic features
I. Elhamdi,
H. Souissi,
O. Taktak,
S. Kammoun,
E. Dhahri,
J. Pina,
B.F.O. Costa,
E. López-Lago
Affiliations
I. Elhamdi
Applied Physics Laboratory, Faculty of Sciences, Sfax University, BP 1171, 3000, Sfax, Tunisia; Corresponding author.
H. Souissi
Applied Physics Laboratory, Faculty of Sciences, Sfax University, BP 1171, 3000, Sfax, Tunisia
O. Taktak
Applied Physics Laboratory, Faculty of Sciences, Sfax University, BP 1171, 3000, Sfax, Tunisia
S. Kammoun
Applied Physics Laboratory, Faculty of Sciences, Sfax University, BP 1171, 3000, Sfax, Tunisia
E. Dhahri
Applied Physics Laboratory, Faculty of Sciences, Sfax University, BP 1171, 3000, Sfax, Tunisia
J. Pina
University of Coimbra, CQC-IMS, Chemistry Department, 3004-535, Coimbra, Portugal
B.F.O. Costa
University of Coimbra, CFisUC, Physics Department, 3004-516, Coimbra, Portugal
E. López-Lago
Departamento de Física Aplicada, Facultade de Óptica e Optometría, Campus Vida, Universidade de Santiago de Compostela (USC), 15782 Galicia, Spain
The ZnAl1.999Ho0.001O4 phosphor, prepared by the solid-state method, crystallizes in the cubic spinel structure. Morphology and chemical composition homogeneity were determined via Energy Dispersive X-ray and SEM analysis. The (Eg) optical band gap was evaluated from the UV/vis absorption spectrum, confirming direct transition behavior according to Tauc's law. The Urbach energy (Eu) in the ZnAl1.999Ho0.001O4 spinel was higher than that in the ZnAl2O4 spinel, indicating increased disorder and a higher concentration of defects due to Ho3+ ions. The penetration depth (δ(λ)), optical extinction (k(λ)), and refractive index (n(λ)) were assessed across wavelengths (λ). The room temperature absorption spectrum revealed several peaks corresponding to the 4f-4f transitions of Ho3+ ions.
