Doping impurity into semiconductor nanocrystals (NCs) is able to create novel optical, electronic, and magnetic functionalities. Recently, dual-emissions from Mn-doped lead chloride perovskites NCs have attracted much attention. However, the mechanisms of doping and energy-transfer to Mn ions of the perovskite NCs are still unclear. In this work, through the newly-developed post-treatment methods, it is found that excess Cl^- can boost the Mn-emission due to the efficient ion diffusion and exchanges during Mn-doping processes. Importantly, a clear slow energy accumulation in the Mn dopants with time constant of ~ 200 ns is revealed from time-resolved photoluminescence (PL) measurements. Together with the doping insensitive band edge PL, these results indicate that the Mn dopants should snatch the energy from non-radiative trap states rather than from band states, which implies an efficient recycling of trapped nonradiative energy for luminescence by the dopants. The developed efficient doping method and proposed mechanism of energy transfer would provide unique insights into the mechanisms of doping. Moreover, fundamental investigations on nanostructure and optical properties are expected to increase its potential in electronic or magnetic applications.

将杂质掺杂到半导体纳米晶体（NCs）中可以创建新颖的光学，电子和磁性功能。近年来，锰掺杂氯化铅钙钛矿NCs的双发射引起了人们的广泛关注。然而，钙钛矿型NCs的向Mn离子掺杂和能量转移的机制仍不清楚。在这项工作中，通过新开发的后处理方法，发现过量的氯^-由于在Mn掺杂过程中有效的离子扩散和交换，可以提高Mn的发射。重要的是，时间分辨的光致发光（PL）测量显示出时间常数约为200 ns的Mn掺杂剂中明显的缓慢能量积累。这些结果与掺杂不敏感的带边缘PL一起，表明Mn掺杂剂应从非辐射陷阱态而不是从带态夺走能量，这意味着被俘获的非辐射能量可以有效地循环利用，以使掺杂剂发光。发达的高效掺杂方法和拟议的能量转移机制将为掺杂机制提供独特的见解。此外，对纳米结构和光学性质的基础研究有望增加其在电子或磁性应用中的潜力。