Wang Shiping, Leng Jing, Sun Qi, Zhao Chunyi, Jin Shengye
State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
J Phys Chem Lett. 2021 Feb 11;12(5):1475-1480. doi: 10.1021/acs.jpclett.1c00017. Epub 2021 Feb 2.
Doping with a transition metal is an effective way to tune the optical properties of semiconductor nanocrystals (NCs). The excitation of transition-metal dopants in NCs is through an internal energy transfer from a host exciton, by which the short-lived exciton energy can be "stored" at the dopant for a significantly longer lifetime. Herein, using Mn-doped CsPbCl perovskite NCs as an example, we report that the long-lived excited state at Mn dopants can be efficiently extracted from the NCs through an external energy transfer (EET) to rhodamine B (RhB) molecules adsorbed on the NC surface. The EET process leads to a delayed RhB emission. The EET rate is found to increase from 0.16 to 1.42 ms as the number of RhB molecules adsorbed per NC increases from 1 to 8.9, leading to energy extraction efficiency up to 71%. This work suggests the potential of Mn-doped perovskite NCs for applications in photon energy conversion and biological imaging.
掺杂过渡金属是调节半导体纳米晶体（NCs）光学性质的有效方法。NCs中过渡金属掺杂剂的激发是通过从主体激子进行的内禀能量转移实现的，借此，短寿命的激子能量可以在掺杂剂处“存储”更长的寿命。在此，以Mn掺杂的CsPbCl钙钛矿NCs为例，我们报道Mn掺杂剂处的长寿命激发态可以通过向吸附在NC表面的罗丹明B（RhB）分子进行的外部能量转移（EET）而有效地从NCs中提取出来。EET过程导致RhB发射延迟。发现随着每个NC上吸附的RhB分子数从1增加到8.9，EET速率从0.16增加到1.42 ms，能量提取效率高达71%。这项工作表明Mn掺杂钙钛矿NCs在光子能量转换和生物成像应用中的潜力。
