Tunable luminescence properties and energy transfer of Tm3+, Dy3+, and Eu3+ co-activated InNbO4 phosphors for warm-white-lighting. Issue 14 (1st November 2016)

• Record Type: Journal Article
• Authors: Su, Liumei; Fan, Xing; Cai, Gemei; Jin, Zhanpeng
• Is Part Of: Ceramics international. Volume 42:Issue 14(2016)
• Page Start: 15994
• Page End: 16006
• Publication Date: 2016-11-01
• Subjects: Photoluminescence -- Color tunable -- Energy transfer -- UV–visible diffuse reflectance -- Structure refinement; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2016.07.105
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: A series of Dy 3+ /Tm 3+ singly-doped, Dy 3+ /Tm 3+ co-doped, and Dy 3+ /Tm 3+ /Eu 3+ tri-doped InNbO4 phosphors have been synthesized by a high-temperature solid-state reaction method. Powder X-ray diffraction (XRD), structure refinement, UV–visible diffuse reflectance (UV-DR) spectrum, photoluminescence excitation (PLE) and emission (PL) spectrum, decay lifetimes and CIE chromaticity coordinate were employed to understand the origins of luminescence properties for synthesized phosphors. Rare-earth activators were determined to be completely dissolved into the host lattice and occupied the 2 e sites deviated from an inversion center by virtue of XRD, structure refinement and photoluminescence features. The photoluminescence excitation spectra of phosphors exhibited a broad excitation band ascribed to charge-transfer of O 2− -Nb 5+, ranging from 200 to 300 nm, and some characteristic excitation peaks associated with energy level transition of RE ions. Under the excitation of UV light, phosphors presented characteristic emission originating from f - f transition within the 4 f configuration of RE ions. With increasing Dy 3+ concentration, emission colors of InNbO4 :Tm 3+, Dy 3+ phosphors can be appropriately tuned from blue to yellow, including almost all the white light region, by means of energy transfer from Tm 3+ to Dy 3+ . Energy transfer rates and efficiencies were calculated according to decay lifetimes and energy transfer mechanism followed a resonant type dipole-dipole interaction with critical distance of 22.23 Å between Tm 3+ and Dy 3+ . By compensating a red component of Eu 3+ ion, single-component warm-white-light emitting was realized in InNbO4 :Tm 3+, Dy 3+, Eu 3+ phosphors. They might be promising candidates for color-tunable light-conversion components in the fabrication of ultraviolet-pumped warm-white-light emitting diodes (WLEDs) for solid-state lighting. Relationship of crystal structures and luminescence properties for InNbO4 and YNbO4 phosphors is as well explicated based on structural analysis.