Structure and luminescent properties of new Dy3+/Eu3+/Sm3+-activated InNbTiO6 phosphors for white UV-LEDs

• Published in: Optical materials Vol. 98; p. 109403
• Main Authors: Su, Liumei, Fan, Xing, Liu, Yijia, Wu, Zhanchao, Cai, Gemei, Wang, Xiaojun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2019
• Subjects: Absorption property; Band gap; Crystal structure; Luminescence; Absorption property; Band gap; Luminescence; Crystal structure
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2019.109403

A series of novel Dy3+/Eu3+/Sm3+-activated InNbTiO6 phosphors have been prepared by conventional solid state reaction method. Based on the structure refinement, RE3+ ions are preferred to occupy the site of In3+ (2e) in the wolframite-type host lattice. According to their UV–visible diffusion reflectance spectra, the band gap and absorption property of un-doped InNbTiO6 sample can be tuned by the dopants. Under UV–visible light excitation, Dy3+/Eu3+/Sm3+ activators in this matrix mainly show emission lines originating from their characteristic f→f transitions. The optimal excitation and emission wavelength are 385 nm and 581 nm for Dy3+, 394 nm and 616 nm for Eu3+, 406 nm and 615 nm for Sm3+. Concentration quenching occurs at 0.06 for Dy3+, 0.06 for Eu3+, and 0.04 for Sm3+, ascribed to resonant q-q, q-q, and d-q interactions, respectively. The luminescence lifetimes are determined to be 0.13, 0.50, and 0.50 ms for InNbTiO6:0.06Dy3+, InNbTiO6:0.06Eu3+, and InNbTiO6:0.04Sm3+, respectively. The Dy3+, Eu3+, and Sm3+ doped phosphors exhibited yellowish-white, red, and orange-red luminescence, respectively. The quantum yields and thermal stability of representative phosphors have been investigated. Present work shows that these new phosphors are promising for application in UV-LED solid-state lighting devices. New yellowish-white, red, and orange-red emitting phosphors have been fabricated using the InNbTiO6 matrix. [Display omitted] •The yellowish-white, red, and orange-red emitting phosphors have been fabricated using the InNbTiO6 matrix.•These activators occupy the site of In3+ (2e) in the wolframite-type host lattice.•Multipolar interactions are responsible for the concentration quenching effect of Dy3+/Eu3+/Sm3+ activators.•PL of representative phosphors have shed light on the effect of Ti4+ ions to luminescent behavior in the same structure.•The thermal stability of InNbTiO6:Sm3+ phosphors is favorable under the excitation of UV-visible light.