A novel single-phase warm white emission phosphor Sr3YAl2O7.5:Bi3+, Eu3+ with energy transfer for UV white LEDs. Issue 48 (29th April 2016)

• Record Type: Journal Article
• Authors: Wang, Yichao; Ding, Jianyan; Li, Yanyan; Yang, Linfen; Ding, Xin; Wang, Yuhua
• Is Part Of: RSC advances. Volume 6:Issue 48(2016)
• Page Start: 42618
• Page End: 42626
• Publication Date: 2016-04-29
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra05445e
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A series of color-tunable warm white-light emitting phosphors Sr3 YAl2 O7.5 : x Bi 3+, y Eu 3+ . Abstract : A novel phosphor Sr3 YAl2 O7.5 : x Bi 3+, y Eu 3+ was successfully synthesized through a high temperature solid-state reaction. The crystal structure, photoluminescence properties, fluorescence decay and thermal quenching properties have been measured and analyzed. The energy transfer mechanism is demonstrated to be a dipole–dipole interaction and the critical distance between the Bi 3+ and Eu 3+ has been calculated. The emission spectra of the Sr3 YAl2 O7.5 :Bi 3+, Eu 3+ phosphors present a blue-green emission of Bi 3+ ions with three broad bands at 370 nm, 410 nm and 505 nm and many characteristic emission lines of Eu 3+ ions, deriving from the allowed 3 P1 – 1 S0 transition of the Bi 3+ ion and the 5 D0 – 7 F j transition of the Eu 3+ ion. By changing the ratio of Bi 3+ concentration and Eu 3+ concentration, we can get a warm white light under ultraviolet excitation. The results give the Commission International deL'Eclairage (CIE) chromaticity coordinates for the white LED as (0.3794, 0.3453) and a correlated color temperature of 3731 K, and the integrated emission intensity at 150 °C remains 66.4% of that measured at room temperature, which indicates that the SYAO:Bi 3+, Eu 3+ phosphor is a very promising candidate for use as a warm UV white light-emitting diode (WLED) phosphor.