Revealing the intrinsic nature of Eu-doped lead phosphate: A study using density functional theory

• Published in: Physica. B, Condensed matter Vol. 666; p. 415104
• Main Authors: Rodrigues, Aldimar Machado, Santos, Willian Oliveira, Rodrigues, Jocelia Silva Machado, de Novais, Erico Raimundo Pereira, de Oliveira, Glaura Caroena Azevedo, Novais, Andrea de Lima Ferreira, Souza, Divanizia do Nascimento
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2023
• Subjects: DFT; Interstitial defect doping; Lead phosphate; Substitutional doping; Substitutional doping; Interstitial defect doping; Lead phosphate; DFT
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2023.415104

Eu3+-doped oxide glasses have received significant research interest due to their luminescent, photoluminescent, and radiation shielding properties, resulting in their application in the nuclear industry. In this work, the structural, electronic, optical, and vibrational properties of two new materials, lead phosphate doped with europium (PbxP8O26:Eu) with x=5 and 6, were investigated using density functional theory with a short-range order description similar to that of crystalline solids. The bandgap energies calculated for the structures with Eu3+ as substitution (x=5) or interstitial (x=6) point defects were 3.5 eV and 1.5 eV, respectively. The structural arrangement and the density of states revealed atomic disorder in both structures, that is, evidence of amorphization. The bandgap energies obtained from the state density calculations agree with those of the ultraviolet–visible (UV–Vis) absorption between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). The UV–Vis spectral signature indicated that the structures are sensitive to UV-C and far-infrared radiation. The vibrational spectra showed a correspondence between the respective bands and the modes of the systems, corroborating the results reported in other works that investigated Eu3+-doped oxide glasses. Both materials showed amorphous features. Our results suggest that both investigated structures can be used as photodetectors, as well as shielding devices for materials exposed to UV-C radiation. •We investigated two new materials PbxP8O26:Eu with x = 5 and 6.•The structural arrangement revealed atomic disorder in both structures.•The gap for the materials as substitution (4.0 eV) and interstitial (1.7 eV) defects.•Our results suggest that both structures can be used as a photodetector.