BaF:Eu,Tb nanofibres achieve enhanced multicolor luminescence and white-light emission multi-channel excitation and energy migration procedure

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 11; no. 31; pp. 1613 - 1624
• Main Authors: Li, Ning, Liu, Xiaohan, Shao, Hong, Qi, Haina, Li, Dan, Yu, Wensheng, Liu, Guixia, Dong, Xiangting
• Format: Journal Article
• Published: 10.08.2023
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d3tc01854g

A series of BaF 2 :Eu 2+/3+ and BaF 2 :Eu 2+/3+ ,Tb 3+ one-dimensional (1D) nanofibres are devised and constructed by using electrospinning and di-crucible fluorination technology without applying reducing gas and protective gas. During the formation process of 1D Eu-doped BaF 2 nanofibres, partial reduction of Eu 3+ is realized, resulting in the co-existence of Eu 2+ and Eu 3+ in the specimen, which is responsible for multicolor luminescence. In the emission spectra of BaF 2 :Eu 2+/3+ nanofibres, the broad peak centered at 377 nm (5d → 4f) belongs to Eu 2+ ions and the narrow peaks at 592 ( 5 D 0 → 7 F 1 ) and 613 nm ( 5 D 0 → 7 F 2 ) belong to Eu 3+ ions. Concurrently, BaF 2 :Eu 2+/3+ nanofibres directly emit luminous color from the blue-light to the yellow-light region by applying different wavelength excitation. Furthermore, by doping green-light-emitting Tb 3+ into the BaF 2 :Eu 2+/3+ nanofibres to acquire BaF 2 :Eu 2+/3+ ,Tb 3+ nanofibres, white-light emission and multicolor luminescence, covering the whole visible light area, are facilely realized via the multi-mode regulation of Eu ion valence states, Eu 2+/3+ and Tb 3+ concentrations, the energy transfer among Eu 2+/3+ and Tb 3+ , and excitation wavelengths, thereby greatly improving the practicability of the neoteric luminescent material. Furthermore, the mechanisms of multicolor luminescence and white-light emission are systematically studied, and the Eu 2+ → Tb 3+ → Eu 3+ energy transfer process in BaF 2 :Eu 2+/3+ ,Tb 3+ nanofibres is further improved and clarified. These new findings are helpful to design and fabricate new types of rare earth-based 1D luminescent nanostructures. BaF 2 :Eu 2+/3+ ,Tb 3+ nanofibres with multicolor luminescence and white-light emission are constructed via electrospinning and di-crucible fluorination technology.