Photoluminescence Spectra Correlations with Structural Distortion in Eu[sup.3+]- and Ce[sup.3+]-Doped Y[sub.3]Al[sub.5-2x] Garnet Phosphors

• Published in: Materials Vol. 17; no. 10
• Main Authors: Ha, Heonji, Yang, Sungjun, Park, Sangmoon
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.05.2024
• Subjects: Photoluminescence; South Korea
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma17102445

Garnet-type materials consisting of Y[sub.3]Al[sub.5-2x](Mg,Ge)xO[sub.12] (x = 0, 1, 2), combined with Eu[sup.3+] or Ce[sup.3+] activator ions, were prepared by a solid-state method to determine the structural and optical correlations. The structure of Y[sub.3]Al[sub.5-2x](Mg,Ge)xO[sub.12] (x = 1, 2) was determined to be a cubic unit cell (Ia-3d), which contains an 8-coordinated Y[sup.3+] site with octahedral (Mg,Al)O[sub.6] and tetrahedral (Al,Ge)O[sub.4] polyhedra, using synchrotron powder X-ray diffraction. When Eu[sup.3+] or Ce[sup.3+] ions were substituted for the Y[sup.3+] site in the Y[sub.3]Al[sub.5-2x](Mg,Ge)xO[sub.12] host lattices, the emission spectra showed a decrease in the magnetic dipole f-f Eu[sup.3+] transition and a redshift of the d-f Ce[sup.3+] transition, related to centrosymmetry and crystal field splitting, respectively. These changes were monitored according to the increase in Mg[sup.2+] and Ge[sup.4+] contents. The dodecahedral and octahedral edge sharing was identified as a key distortion factor for the structure-correlated luminescence in the Eu[sup.3+]/Ce[sup.3+]-doped Y[sub.3]Al[sub.5-2x](Mg,Ge)xO[sub.12] garnet phosphors.