【Angew.Chem.】中山大学吴武强|动力学截留高密度间隙锰离子实现无浓度淬灭的长余辉钙钛矿发光（PLQY达94.2%，余辉超4000秒）
【Angew.Chem.】中山大学吴武强|动力学截留高密度间隙锰离子实现无浓度淬灭的长余辉钙钛矿发光（PLQY达94.2%，余辉超4000秒）
文章标题：Kinetically Trapped High-Density Interstitial Mn2+ Enables Concentration-Quenching-Free Persistent Luminescence in CsCdCl3 Perovskites 文章作者：Qiudong Duan, Shuo Zhang, Zhenhua Song, Yuxuan Fang, Guo Yang, Zhirou Chen, Huanyu Chen, Ying Tan, Wenhuai Feng, Wu-Qiang Wu 文章链接：https://doi.org/10.1002/anie.6735869
长余辉钙钛矿的浓度淬灭瓶颈与研究动因
长余辉发光材料在防伪、光学存储和生物成像等领域受到广泛关注，全无机金属卤化物钙钛矿因兼具溶液可加工性与结构刚性成为前沿热点体系。然而，传统无机余辉材料依赖千度以上的高温固相合成且难于加工，而有机余辉材料环境稳定性差；更关键的是，在现有的卤化物钙钛矿体系中，锰离子掺杂主要基于热力学平衡条件下的晶格取代位点掺杂，高掺杂浓度下严重的锰-锰相互作用会导致显著的浓度淬灭，难以协同优化发光中心与陷阱态能级分布。针对传统取代掺杂容量有限、水热合成条件苛刻以及浓度淬灭等短板，本文提出在室温下通过动力学控制将高密度锰离子截留在间隙位点，旨在打破浓度淬灭限制，构建协同优化的能级陷阱网络，为大规模制备高性能、多功能长余辉钙钛矿材料提供全新路径。
Fig.1 Kinetically controlled interstitial Mn2+ incorporation and its structural and electronic consequences in CsCdCl3. (a) Schematic illustration of the room-temperature, kinetically controlled synthesis of CTAB-assisted interstitial Mn2+-doped CsCdCl3, in which CTAB served as a multifunctional modulator by realizing Br–-induced lattice expansion to increase the interstitial Mn2+ doping capacity while simultaneously suppressing defect-assisted non-radiative recombination. Crystal structures of pristine CsCdCl3, CsCdCl3 with CTAB and CTAB-assisted interstitial Mn2+-doped CsCdCl3 are shown for comparison. (b) XRD patterns of CsCdCl3: x% Mn2+ and CsCdCl3: x% Mn2+ with CTAB (x = 0, 5, 15, 20), showing phase purity and systematic peak shifts associated with halogen substitution and Mn2+ incorporation. (c) DFT-calculated formation energies of Mn2+ in substitutional and interstitial configurations in the CsCdCl3 lattice. (d) Calculated electronic band structure, (e) square of the electric dipole transition dipole moment (TDM), and (f) total densities of state (TDOS) and partial densities of state (PDOS) of CsCdCl3: 20% Mn2+ with CTAB.
动力学间隙掺杂构建策略与发光动力学实验验证
本研究采用理论计算与室温超快合成相结合的技术路线。本文首次提出利用十六烷基三甲基溴化铵作为溴源与结晶调节剂的双功能分子，在室温常压下利用毫秒级的快速成核动力学过程，将锰离子原位“动力学截留”在因溴离子取代而膨胀的氯化铯镉晶格间隙中，有效绕过热力学优先的镉位点取代途径。密度泛函理论计算证实间隙锰离子的形成能（-0.70电子伏特）显著低于取代位点（-0.23电子伏特）；结合电子顺磁共振呈现出的典型六重超精细分裂信号，证明高浓度掺杂下锰离子仍保持高度磁隔离，从本质上抑制了锰离子团聚与非辐射能量耗散。
实验系统对比了未掺杂、传统无表面活性剂修饰以及引入表面活性剂调控的系列样品。稳态与瞬态光谱测试表明，在高达20%的锰离子掺杂量下，体系未出现常规体系在5%浓度即发生的猝灭现象，光致发光量子产率达到了94.2%（相比未掺杂基线的13.9% 提升近6倍），并在环境储存两个月后保持率超过95%；余辉衰减时间突破4000秒。热释光谱分析明确了体系构建了包含0.64电子伏特、0.92电子伏特和1.06电子伏特的分级陷阱网络，使得材料在77至407开尔文宽温区内展现出反常的热辅助增强发光行为。
在放大生产与器件应用验证中，该合成工艺在室温下仅需20秒即可完成单批次超过10克的反应，成本仅约每克1.16美元。将粉体与聚二甲基硅氧烷复合制备成面积达50.24平方厘米的柔性发光凝胶后，基于双发射通道荧光强度比构建了比率型光学温度计（最大相对灵敏度达每开尔文3.63%，绝对灵敏度达每开尔文1.15），并成功展示了基于紫外写入与热擦除的可重写光学存储，以及结合时间与温度多重响应的“8888”和点阵动态防伪加密系统。
Fig.2 Structural, electronic, and magnetic characterization of interstitial Mn2+-doped CsCdCl3. (a) Raman spectra of CsCdCl3, CsCdCl3 with CTAB, CsCdCl3: 5% Mn2+, CsCdCl3: 20% Mn2+ and CsCdCl3: 20% Mn2+ with CTAB. (b) High resolution XPS spectra of the Mn 2p core levels and (c) Br 3d core levels. (d) SEM image of CsCdCl3: 20% Mn2+ with CTAB. (e) Statistical grain size distribution histogram of CsCdCl3: 20% Mn2+ with CTAB. (f) EPR spectra of CsCdCl3: x% Mn2+ with CTAB (x = 2, 20) measured at room temperature.
Fig.3 Excitation-dependent luminescence and ultralong persistent luminescence behaviors of interstitial Mn2+-doped CsCdCl3. (a) PLE spectra monitored at 495 nm for pristine CsCdCl3 and CsCdCl3: x% Mn2+ with CTAB (x = 0, 2, 20). (b) PLE spectra monitored at 585 nm for CsCdCl3: x% Mn2+ with CTAB (x = 2, 10, 20). (c) Steady-state PL spectra of pristine CsCdCl3 and CsCdCl3: x% Mn2+ with CTAB (x = 0, 2, 20) under 254 nm excitation. (d) Photographs of fluorescence and persistent luminescence behaviors of pristine CsCdCl3 and CsCdCl3: x% Mn2+ with CTAB (x = 0, 2, 5, 10, 15, 20, 30, 40, 50) under 254 nm excitation. (e) Afterglow decay curves of CsCdCl3: x% Mn2+ with CTAB (x = 0, 20) monitored at 495 nm. (f) Afterglow decay curve of CsCdCl3: 20% Mn2+ with CTAB monitored at 585 nm.
Fig.4 Trap-state engineering, thermal stability, and excited-state dynamics of interstitial Mn2+-doped CsCdCl3. (a) PLQY values of pristine CsCdCl3 and CsCdCl3: x% Mn2+ with CTAB (x = 0, 20) under 270 nm excitation. (b) TL spectra of pristine CsCdCl3 and CsCdCl3: x% Mn2+ with CTAB (x = 0, 20). (c) Pseudo-color temperature-dependent PL contour map (77–407 K) of CsCdCl3 with CTAB under 254 nm excitation. (d) Pseudo-color temperature-dependent PL contour map (77–467 K) of CsCdCl3: 20% Mn2+ with CTAB under 254 nm excitation. (e) TRPL decay curves monitored at 495 nm for pristine CsCdCl3 and CsCdCl3: x% Mn2+ with CTAB (x = 0, 20). (f) TRPL decay curves monitored at 585 nm for CsCdCl3: x% Mn2+ with CTAB (x = 2, 20, 30). (g) Femtosecond transient absorption (fs-TA) spectra of CsCdCl3: 20% Mn2+ with CTAB under 320 nm excitation. (h) TA decay dynamics of CsCdCl3: 20% Mn2+ with CTAB probed at 585 nm. (i) Schematic illustration of the UPL mechanism in interstitial Mn2+-doped CsCdCl3 with CTAB, including carrier trapping/detrapping pathways, host-to-Mn2+ energy transfer, Cl−→Mn2+ CTB excitation, and temperature-dependent emission processes.
Fig.5 Optical thermometry and multidimensional information encryption based on interstitial Mn2+-doped CsCdCl3. (a) Temperature-dependent FIR (I585 nm/I495 nm) values of CsCdCl3: 20% Mn2+ with CTAB. (b) Calculated Sr and Sa values of the CsCdCl3: 20% Mn2+ with CTAB-based optical thermometer over the temperature range of 77–317 K. (c) Reversible variation of FIR (I585 nm/I495 nm) during repeated heating-cooling cycles. (d) Schematic illustration of rewritable optical information storage based on UV writing, persistent luminescence and thermal erasing processes using the flexible luminescent gel. (e) Multilevel dynamic optical encryption pattern constructed in the shape of “8888”. (f) Time-sequence photographs illustrating the dynamic evolution of the dot-matrix encryption pattern under different excitation and afterglow conditions, demonstrating temporally programmable information encoding and decoding.
核心创新机制与性能突破
本工作的核心创新在于突破了传统热力学平衡取代掺杂的认知局限，首次开辟了卤化物钙钛矿在室温下的动力学间隙掺杂与晶格膨胀协同调控机制，完美化解了发光中心高浓度淬灭与陷阱分布失调的核心痛点。材料在室温下实现了94.2%的超高发光量子产率、超4000秒的长余辉、20秒克级极速合成与优异的抗热猝灭性能，极大拓宽了全无机发光材料在智能传感、信息加密与柔性光子学领域的实用化前景。
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