Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai 200433, P.R. China.
Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai 200433, P.R. China.
J Phys Chem Lett. 2023 Jun 22;14(24):5580-5585. doi: 10.1021/acs.jpclett.3c01046. Epub 2023 Jun 12.
Colloidal CsPbX (X = Br, Cl, or I) perovskite nanocrystals (PNCs) have emerged as low-cost, high-performance light-emitting materials, whereas the toxicity of lead limits their applications. Europium halide perovskites offer promising alternatives to lead-based perovskites due to their narrow spectral width and high monochromaticity. Nonetheless, the photoluminescence quantum yields (PLQYs) of CsEuCl PNCs have been very low (∼2%). Herein, Ni-doped CsEuCl PNCs have been first reported, exhibiting bright blue emission centered at 430.6 ± 0.6 nm with a full width at half-maximum of 23.5 ± 0.3 nm and a PLQY of 19.7 ± 0.4%. To the best of our knowledge, this is the highest PLQY value reported for CsEuCl PNCs so far, an order of magnitude higher than in previous work. DFT calculations demonstrate that Ni enhances PLQY by concurrently increasing the oscillator strength and removing Eu which hinders the photorecombination process. B-site doping offers a promising approach to enhance the performance of lanthanide-based lead-free PNCs.
胶体 CsPbX（X=Br、Cl 或 I）钙钛矿纳米晶体（PNCs）作为低成本、高性能的发光材料而崭露头角，而铅的毒性限制了其应用。由于其光谱宽度窄、单色性高，铕卤化物钙钛矿为基于铅的钙钛矿提供了有前途的替代品。尽管如此，CsEuCl PNCs 的光致发光量子产率（PLQY）一直非常低（约为 2%）。本文首次报道了 Ni 掺杂 CsEuCl PNCs，其表现出明亮的蓝色发射，中心位于 430.6±0.6nm，半峰全宽为 23.5±0.3nm，PLQY 为 19.7±0.4%。据我们所知，这是迄今为止报道的 CsEuCl PNCs 的最高 PLQY 值，比以前的工作高一个数量级。DFT 计算表明，Ni 通过同时增加振子强度和去除阻碍光重组过程的 Eu 来提高 PLQY。B 位掺杂为提高基于镧系元素的无铅 PNCs 的性能提供了一种有前途的方法。
