Spin dynamics of excitons, carriers and nuclei in metal halide perovskite nanostructures

该项目的目标是研究低维金属卤化物钙钛矿纳米结构(纳米晶和2D层)中激子复合体的能量和自旋结构，并阐明量子限制对自旋相关参数和自旋相关现象的作用。我们计划通过与理论家的合作来支持技术和实验研究。合成的样品将是不同尺寸和化学成分的全无机和有机-无机钙钛矿纳米晶，以及厚度从1到5个单分子层的2D层状材料。为了验证稀磁半导体的概念，还将用锡取代铅作为无铅材料或用磁性锰离子掺杂来制备二维样品。在实验研究方面，将使用光学技术，包括低温、高达60T的强磁场、偏振分析、时间分辨率从200飞秒到秒以及高光谱分辨率。我们将通过测量g因子、自旋驰豫和自旋相干时间以及确定自旋-自旋相互作用的机制，重点研究载流子(电子和空穴)、激子(中性和带电的)和原子核自旋相互作用系统的自旋依赖现象和自旋动力学。在掺锰的样品中，还会涉及到与局域的锰自旋的相互作用，这通常会导致巨大的磁光效应。我们将寻找新的物理现象和已知现象的新机制，这些现象是由钙钛矿的独特性质提供的。所获得的知识将用于优化发光设备的技术和参数，并用于测试钙钛矿型纳米结构应用于自旋电子学的可行性。

The project goal is to study energy and spin structure of exciton complexes in low dimensional metal halide perovskites nanostructures (nanocrystals and 2D layers) and to clarify the role of quantum confinement on the spin-related parameters and on the spin-dependent phenomena. We plan technological and experimental studies being supported by collaboration with theorists. Synthesized samples will be all-inorganic and organic-inorganic lead halide perovskite nanocrystals of various sizes and chemical compositions, and 2D layered materials with thickness ranged from 1 to 5 monolayers. Also, 2D samples will be fabricated with Pb substituted by Sn for lead-free materials or doped with magnetic Mn-ions to prove the concepts of diluted magnetic semiconductors. For experimental studies optical techniques, involving low temperatures, high magnetic fields up to 60 T, polarization analysis, time-resolution in temporal range from 200 fs to seconds and high spectral resolution will be used. We will focus on spin-dependent phenomena and spin dynamics of interacting spin systems of carriers (electrons and holes), excitons (neutral and charged) and nuclei spins by measuring g-factors, spin relaxation and spin coherence times and identifying mechanisms of spin-spin interactions. In Mn-doped samples interaction with localized Mn-spins will be additionally involved, which typically results in giant magneto-optical effects. We will search for new physical phenomena and new regimes of the known phenomena provided by the unique properties of the perovskites. The gained knowledge will be used for optimizing technology, parameters of light-emitting devices and for testing the feasibility of the perovskite nanostructures for spintronics applications.