Abstract A long persistent phosphor (LPP) CaZnGe2O6: Cr3+ has been rationally designed and successfully fabricated. The weak crystal field surrounding Cr3+ activator enables an afterglow emission band 700–1200 nm almost covering the biological transparency window. In this work, a feasible route of Mn2+ codoping is suggested to precisely control the spectral shape, which further meets the demand of wide range and steady response to different photo-detectors in the biological transparency window. An interestingly synchronous improvement of persistent duration of Cr3+ and Mn2+ emission center is discovered in this process. Meanwhile, this codoping technique also achieves the enhancement of afterglow-excitation intensity. The design approach employed here inherently involves the ingenious engineering for combining the isolated traps in Cr3+, Mn2+ singly doped LPP, and for forming a continuous-distribution trap in Cr3+, Mn2+ co-doped LPP according to the thermoluminescent measurement. The highlighted redeployment of trap distribution will opens a vista of potential avenues for LPP design, afterglow mechanism analysis and functionalized application of bio imaging.

中文翻译：

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可调谐 NIR 长余辉发光和过渡金属掺杂弱晶场 CaZnGe 2 O 6 中陷阱分布相关激发增强的发现

摘要 一种长余辉荧光粉（LPP）CaZnGe2O6:Cr3+已被合理设计并成功制备。Cr3+ 激活剂周围的弱晶体场使 700-1200 nm 的余辉发射带几乎覆盖了生物透明窗口。在这项工作中，提出了一种可行的 Mn2+ 共掺杂路线来精确控制光谱形状，进一步满足生物透明窗口中对不同光电探测器的宽范围和稳定响应的需求。在这个过程中发现了 Cr3+ 和 Mn2+ 排放中心持续持续时间的有趣同步改进。同时，这种共掺杂技术还实现了余辉激发强度的增强。这里采用的设计方法固有地涉及结合 Cr3+ 中孤立陷阱的巧妙工程，Mn2+ 单掺杂 LPP，并根据热释光测量在 Cr3+、Mn2+ 共掺杂 LPP 中形成连续分布陷阱。突出显示的陷阱分布的重新部署将为 LPP 设计、余辉机制分析和生物成像的功能化应用开辟潜在途径。