Yeh I-Hsuan, Ghobadifard Mahdieh, Feng Lin, Galievsky Victor, Radovanovic Pavle V
Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Nano Lett. 2024 Aug 28;24(34):10554-10561. doi: 10.1021/acs.nanolett.4c02640. Epub 2024 Aug 16.
Low-dimensional metal halide perovskites have unique optical and electrical properties that render them attractive for the design of diluted magnetic semiconductors. However, the nature of dopant-exciton exchange interactions that result in spin-polarization of host-lattice charge carriers as a basis for spintronics remains unexplored. Here, we investigate Mn-doped CsPbCl nanocrystals using magnetic circular dichroism spectroscopy and show that Mn dopants induce excitonic Zeeman splitting which is strongly dependent on the nature of the band-edge structure. We demonstrate that the largest splitting corresponds to exchange interactions involving the excited state at the M-point along the spin-orbit split-off conduction band edge. This splitting gives rise to an absorption-like -term excitonic MCD signal, with the estimated effective -factor () of ca. 70. The results of this work help resolve the assignment of absorption transitions observed for metal halide perovskite nanocrystals and allow for a design of new diluted magnetic semiconductor materials for spintronics applications.
低维金属卤化物钙钛矿具有独特的光学和电学性质，这使其在稀磁半导体设计中具有吸引力。然而，作为自旋电子学基础的、导致主体晶格电荷载流子自旋极化的掺杂剂 - 激子交换相互作用的本质仍未得到探索。在此，我们使用磁圆二色光谱研究了Mn掺杂的CsPbCl纳米晶体，并表明Mn掺杂剂会诱导激子塞曼分裂，这强烈依赖于带边结构的性质。我们证明，最大分裂对应于沿着自旋 - 轨道分裂导带边缘在M点涉及激发态的交换相互作用。这种分裂产生了一个类似吸收的项激子MCD信号，估计的有效因子（）约为70。这项工作的结果有助于解决金属卤化物钙钛矿纳米晶体观察到的吸收跃迁的归属问题，并有助于设计用于自旋电子学应用的新型稀磁半导体材料。
