Demystifying and Controlling the Exciton Fine Structure in Single Inorganic Perovskite Nanoplatelets

揭秘并控制单一无机钙钛矿纳米片中的激子精细结构

• 批准号: 520014557
• 负责人: Professor Dr. Gerd Bacher
• 金额: --
• 依托单位: Laboratory of Inorganic Chemistry
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/520014557?language=en
• 关键词: Demystifying; Controlling; Exciton; Fine; Structure

The high versatility of lead halide perovskite nanocrystals opened enormous prospects for classical light emitting devices as well as for quantum emitters that are highly required, e.g., for quantum information technology. The latter requires a detailed understanding of the exciton transitions in individual nanocrystals and their control by tailoring the nanocrystals and by applying well-defined external fields. Hitherto, the random orientation of individual nanocrystals in single particle experiments inhibits the assignment of the individual components of the exciton fine structure to the respective crystal axes. Moreover, magnetic as well as electrical fields have already been applied to externally control the emission pattern of individual lead halide perovskite nanocrystals. However, the lack of control of the single nanocrystal orientation with respect to the field directions hampers the determination of the g-factor and the induced and permanent electrical dipoles with respect to the crystal axes until now. The objective of this proposal is the investigation of the exciton fine structure in single anisotropic size engineered CsPbBr3 nanoplatelets and its manipulation by directional electric and magnetic fields that are well-defined with respect to the crystal axes. This novel idea makes use of our recent discovery that the distinct shape anisotropy and high stability of the nanoplatelets allow deposition of single nanoplatelets with a clearly defined (flat) alignment on a pre-patterned substrate and enable determination of their absolute orientation by emission polarisation measurements. Applying magnetic as well as electrical fields to single nanoplatelets, we will derive the anisotropy of the g-factor as well as the permanent electrical dipole moments and the electrical polarizability with respect to the crystal axes. We envision to elaborate the potential of applied electric fields along specific crystal axes to control and finally eliminate the fine structure splitting on the route towards entangled photon sources based on single lead halide perovskite nanocrystals.

卤化铅钙钛矿纳米晶体的高度通用性为经典发光器件以及高度需要的量子发射器（例如，用于量子信息技术。后者需要详细了解个别纳米晶体中的激子跃迁及其通过定制纳米晶体和通过施加明确的外部场来控制。然而，在单粒子实验中各个纳米晶体的随机取向抑制了激子精细结构的各个组分到各自晶轴的分配。此外，磁场和电场已经被应用于外部控制单个卤化铅钙钛矿纳米晶体的发射模式。然而，缺乏控制的单方向相对于磁场方向阻碍了g因子和诱导和永久电偶极子相对于晶轴的测定，直到现在。该提案的目的是调查激子精细结构在单一各向异性尺寸工程CsPbBr 3纳米片和其操纵的定向电场和磁场是明确定义的相对于晶轴。这种新的想法利用了我们最近的发现，即纳米片的独特形状各向异性和高稳定性允许在预图案化的衬底上沉积具有明确定义的（平坦的）对准的单个纳米片，并且能够通过发射偏振测量来确定它们的绝对取向。将磁场和电场施加到单个纳米片上，我们将推导出g因子的各向异性以及永久电偶极矩和相对于晶轴的电极化率。我们设想详细阐述沿沿着特定晶轴施加的电场的潜力，以控制并最终消除基于单个卤化铅钙钛矿纳米晶体的纠缠光子源的路线上的精细结构分裂。