Abstract Bismuth-doped SrAl4O7 powders were synthesized via modified Pechini process and their photoluminescence, radioluminescence and thermoluminescence properties were studied and discussed. Obtained results showed that in studied materials bismuth is present in two valence states, Bi3+ and Bi2+. Upon UV excitation SrAl4O7:Bi powders yield broad multicomponent luminescence in the 350–670 nm range, associated with the 3P0,1 → 1S0 transition of Bi3+ ions, and the most intense component located in green (λmax = 515 nm) part of spectrum. It was found that the emission spectral distribution is excitation wavelength-dependent. By changing the excitation wavelength in the 270–340 nm range the emission colour can be modulated from blue, through bluish-cyan to green. The studied phosphors also showed broad-band 2P3/2 → 2P1/2 Bi2+ emission in deep red region centered at around 710 nm. This luminescence was found predominant in radioluminescence and thermoluminescence spectra, which is deemed unique for bismuth-doped materials. The Bi2+ 630–830 nm emission might be attractive for bioimaging as it appears in the Ist biological window and may be utilized for deep red scintillation.

中文翻译：

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新型 Bi 掺杂 SrAl4O7 荧光粉中 Bi3+ 和 Bi2+ 离子的发光

摘要 采用改进的Pechini法合成了铋掺杂的SrAl4O7粉体，并对其光致发光、辐射致发光和热致发光性能进行了研究和讨论。获得的结果表明，在所研究的材料中，铋以两种价态 Bi3+ 和 Bi2+ 存在。在紫外线激发下，SrAl4O7:Bi 粉末在 350–670 nm 范围内产生广泛的多组分发光，与 Bi3+ 离子的 3P0,1 → 1S0 跃迁相关，并且最强的组分位于光谱的绿色 (λmax = 515 nm) 部分。发现发射光谱分布与激发波长有关。通过在 270-340 nm 范围内改变激发波长，可以将发射颜色从蓝色调制到蓝青色到绿色。所研究的磷光体还在以 710 nm 附近为中心的深红色区域显示出宽带 2P3/2 → 2P1/2 Bi2+ 发射。发现这种发光在辐射发光和热释光光谱中占主导地位，这被认为是掺铋材料所独有的。Bi2+ 630–830 nm 发射可能对生物成像很有吸引力，因为它出现在 Ist 生物窗口中，并可用于深红色闪烁。