Exchange interactions in wavefunction engineered, transition metal doped 2D hetero-nanoplatelets

波函数工程、过渡金属掺杂二维异质纳米片中的交换相互作用

• 批准号: 399377107
• 负责人: Professor Dr. Gerd Bacher
• 金额: --
• 依托单位: Lehrstuhl Werkstoffe der Elektrotechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/399377107?language=en
• 关键词: Exchange; interactions; wavefunction; engineered; transition

Recent advances in colloidal nanocrystal chemistry allows for the realization of wavefunction- engineered nanoplatelets with core-shell, core-crown or core-crown-shell architectures. The quasi-two dimensional (2D) density of states, combined with strong quantum and dielectric confinement results in exciting electronic and optoelectronic properties, opening a pathway for innovative applications.In this project we intend to expand the functionalities of this novel material class by transition metal doping with monolayer accuracy. The required materials – which are worldwide unique - will be provided by our project partner, Prof. H.V. Demir at Nanyang Technological University, Singapore. Quasi type II (CdSe/CdS) and type II (CdSe/CdTe) heterostructures doped with manganese or cobalt in the shell / crown will represent the material basis for investigating s,p –d exchange interactions between magnetic dopants and charge carriers. Hetero-nanoplatelets with monolayer thickness control and well-defined doping positions will be investigated, where the wavefunction distribution of ground and excited carrier states will be engineered towards a targeted overlap with the transition metal dopants.The fact that in such nanoplatelets a variety of ground and excited states of different hole character (heavy hole, light hole, split-off hole) can be separated in magneto-optical experiments due to pronounced excitonic resonances will individually give access to s-d and p-d exchange constants in reduced dimensions. We intend to extract the size-dependent s-d and p-d exchange constants for both, Mn- and Co-doped nanoplatelets and envision to optically generate long living magnetic polarons with defined magnetization axis utilizing the defined architecture of type II hetero-nanoplatelets. Probing the ligand field transition of the Co2+ ion in the crystal matrix, experimental access to local strain distributions at the hetero-interface is expected by changing the dopant position with respect to the interface with monolayer accuracy.

胶体微球化学的最新进展允许实现具有核-壳、核-冠或核-冠-壳结构的波函数工程化纳米片。准二维（2D）态密度，结合强量子和介电限制，激发电子和光电性能，为创新应用开辟了道路。在这个项目中，我们打算通过单层精确的过渡金属掺杂来扩展这种新型材料的功能。所需的材料-这是世界上唯一的-将由我们的项目合作伙伴，教授H. V.德米尔在南洋理工大学，新加坡提供。在壳/冠中掺杂锰或钴的准II型（CdSe/CdS）和II型（CdSe/CdTe）异质结构将代表研究磁性掺杂剂与电荷载流子之间的s，p-d交换相互作用的材料基础。将研究具有单层厚度控制和良好限定的掺杂位置的异质纳米片，其中基态和激发载流子态的波函数分布将被设计成与过渡金属掺杂剂的目标重叠。（重空穴、轻空穴、分裂空穴）可以在磁光实验中分离，这是因为显著的激子共振将单独地给出在减小的维度中的S-D和P-D交换常数。我们打算提取的大小依赖的s-d和p-d交换常数，锰和钴掺杂的纳米片和设想，光学产生长寿命的磁极化子与定义的磁化轴利用定义的架构的II型异质纳米片。探测的配位场过渡的Co 2+离子在晶体基质中，实验获得的局部应变分布在异质界面预期通过改变掺杂剂的位置相对于单层精度的接口。