Huang Yuling, Chen Congcong, Gong Shaokuan, Hu Qiushi, Liu Jingjing, Chen Hongyu, Mao Lingling, Chen Xihan
Shenzhen Key Laboratory of Intelligent Robotics and Flexible Manufacturing Systems, SUSTech Energy Institute for Carbon Neutrality, Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China.
J Am Chem Soc. 2024 May 1;146(17):12225-12232. doi: 10.1021/jacs.4c03532. Epub 2024 Apr 18.
The control of spin relaxation mechanisms is of great importance for spintronics applications as well as for fundamental studies. Layered metal-halide perovskites represent an emerging class of semiconductors with rich optical spin physics, showing potential for spintronic applications. However, a major hurdle arises in layered metal-halide perovskites with strong spin-orbit coupling, where the spin lifetime becomes extremely short due to D'yakonov-Perel' scattering and Bir-Aronov-Pikus at high carrier density. Using the circularly polarized pump-probe transient reflection technique, we experimentally reveal the important scattering for spin relaxation beyond the electron-hole exchange strength in the Dion-Jacobson (DJ)-type 2D perovskites (3AMP)(MA)PbI [3AMP = 3-(aminomethyl)piperidinium, = 1-4]. Despite a more than 10-fold increase in carrier concentration, the spin lifetimes for = 3 and 4 are effectively maintained. We reveal neutral impurity and polar optical phonon scatterings as significant contributors to the momentum relaxation rate. Furthermore, we show that more octahedral distortions induce a larger deformation potential which is reflected on the acoustic phonon properties. Coherent acoustic phonon analysis indicates that the polaronic effect is crucial in achieving control over the scattering mechanism and ensuring spin lifetime protection, highlighting the potential of DJ-phase perovskites for spintronic applications.
自旋弛豫机制的控制对于自旋电子学应用以及基础研究都非常重要。层状金属卤化物钙钛矿是一类新兴的半导体，具有丰富的光学自旋物理特性，在自旋电子学应用中显示出潜力。然而，在具有强自旋轨道耦合的层状金属卤化物钙钛矿中出现了一个主要障碍，在高载流子密度下，由于D'yakonov-Perel'散射和Bir-Aronov-Pikus效应，自旋寿命变得极短。利用圆偏振泵浦-探测瞬态反射技术，我们通过实验揭示了在Dion-Jacobson（DJ）型二维钙钛矿（3AMP）（MA）PbI[3AMP = 3-(氨甲基)哌啶鎓， = 1-4]中，除了电子-空穴交换强度之外，对自旋弛豫起重要作用的散射。尽管载流子浓度增加了10倍以上，但 = 3和4时的自旋寿命仍能有效保持。我们揭示了中性杂质和极性光学声子散射是动量弛豫率的重要贡献因素。此外，我们表明更多的八面体畸变会诱导更大的形变势，这反映在声学声子特性上。相干声学声子分析表明，极化子效应对于实现对散射机制的控制和确保自旋寿命保护至关重要，突出了DJ相钙钛矿在自旋电子学应用中的潜力。
