Tao Jia Qi, Zhang Hu, Bi Wengang, Liu Xiaohui, Fan Chao, Sun Chun
Tianjin Key Laboratory of Electronic Materials and Devices, School of Electronics and Information Engineering, Hebei University of Technology, 5340 Xiping Road, Tianjin, 300401, P. R. China.
Baotou Teachers' College, Inner Mongolia University of Science and Technology, Baotou, P.R. China.
Dalton Trans. 2022 Jul 26;51(29):11021-11028. doi: 10.1039/d2dt01102f.
Ultrathin 2D perovskite nanoplatelets (NPLs) have many excellent optical properties including narrow absorption and emission spectra, and large exciton binding energies. Doping Mn into perovskite NPLs also introduces strong orange luminescence due to the d-d de-excitation recombination. However, it is very challenging to synthesize Mn doped ultrathin perovskite NPLs. Here, we report the successful development of a room temperature method for Mn ion doped perovskite NPLs. The impact of the Mn concentration on their optical properties has been systematically investigated. The highest PLQY is up to 71% when the Mn doping level is 38.6%. Furthermore, we have observed a self-purification effect of these = 2 NPLs, where the Mn ions were ejected from the = 2 NPLs and injected into the = 3 NPLs. An efficient energy transfer from the = 2 host to the = 3 NPLs has also been found. Additionally, we have used this fast ejecting and injecting property to fabricate an anti-counterfeiting film. The film shows weak blue and strong orange color under room temperature and high temperature, respectively. Most importantly, the process can be repeated several cycles without damage, which shows great potential for anti-counterfeiting applications.
超薄二维钙钛矿纳米片（NPLs）具有许多优异的光学特性，包括窄吸收和发射光谱以及大的激子结合能。将锰掺杂到钙钛矿NPLs中还会由于d-d去激发复合而引入强烈的橙色发光。然而，合成锰掺杂的超薄钙钛矿NPLs极具挑战性。在此，我们报告了一种成功开发的用于锰离子掺杂钙钛矿NPLs的室温方法。系统研究了锰浓度对其光学特性的影响。当锰掺杂水平为38.6%时，最高的光致发光量子产率（PLQY）高达71%。此外，我们观察到了这些n = 2 NPLs的自净化效应，其中锰离子从n = 2 NPLs中被弹出并注入到n = 3 NPLs中。还发现了从n = 2主体到n = 3 NPLs的高效能量转移。此外，我们利用这种快速弹出和注入特性制备了一种防伪薄膜。该薄膜在室温下显示出微弱的蓝色，在高温下显示出强烈的橙色。最重要的是，该过程可以重复几个循环而不损坏，这显示出在防伪应用方面的巨大潜力。
