Energy transfer mediated single-phased white light emission in Bi3+-Eu3+ codoped Ba3YGa2O7.5 for WLED

• Published in: Journal of alloys and compounds 2022-11, Vol.923, p.166419, Article 166419
• Main Authors: Wei, Shuai, Li, Zhijun, Lyu, Zeyu, Sun, Dashuai, Shen, Sida, Wang, Jianhui, Zhuo, Chengyu, You, Hongpeng
• Format: Article
• Language: English
• Subjects: Bi3; Color; Crystal structure; Dipole interactions; Energy transfer; Europium; High temperature; Light emission; Perovskites; Phosphor; Phosphors; White light; WLED
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.166419

In this work, we provide a paradigm how to realize white light emission by utilizing the energy transfer from the Bi3+ to Eu3+ ions. First, a novel Bi3+ activated phosphor set of highly oxygen-deficient perovskite derivatives (Ba3YGa2O7.5, BYGO) were synthesized through the conventional high-temperature solid-state method. The crystal structure was confirmed by Rietveld refinement. Then, Eu3+ was introduced to the phosphor composition to construct energy transfer pathway with Bi3+. The emission color of the BYGO:Bi3+,Eu3+ phosphors can be changed from cyan to white and orange-red by altering the Bi3+/Eu3+ doping ratio. The energy transfer from the Bi3+ to Eu3+ ions was ascribed to dipole-dipole interaction. Finally, a single-component WLED device with a color-rendering index of 84.9 was successfully prepared by employing a near-ultraviolet chip and the BYGO:Bi3+,Eu3+ phosphors. This work not only indicates that the as-prepared BYGO:Bi3+,Eu3+ phosphors are a potential candidate for near-ultraviolet WLED, but also demonstrated that energy transfer is an avenue for single-phased white light emission. [Display omitted] •The cyan phosphor Ba3YGa2O7.5:Bi3+ was synthesized for the first time.•The energy transfer from the Bi3+ to Eu3+ ions is constructed.•Adjusting the doping ratio of Bi3+ to Eu3+ realizes multicolor emission.•A single-phased WLED with a color rendering index of 84.9 was achieved.