Formation and Charge Carrier Dynamics of Hybrid I-III-VI2 Nanoheterostructures

I-III-VI 2半导体线CuInS 2是有前途的材料，因为它们不含有毒的重金属，如CdSe，PbS或甲基铵铅钙钛矿。然而，在纳米晶体的形式中，I-III-VI 2半导体的光物理学尚未得到很好的理解，因为受激电荷载流子倾向于定位在本征缺陷处，而不是呈现由颗粒尺寸定义的激子状态。在I-III-VI 2半导体中存在不同的电荷载流子动力学模型，但没有一个可以被明确地证明或反驳。为了测试这些模型，并确定I-III-VI 2半导体的电荷载流子动力学的异质结构的合成提出，其中所调查的材料共享一个界面，具有良好的特性，第二材料。界面的选择要使激发的电子和空穴在空间上分离。通过这种方式，可以量化它们对电荷载流子动力学的贡献并测试不同的模型。此外，该项目将通过异质界面的形成产生关于三元化合物中一价阳离子的流动性的信息。这个量对于异质结构的制造和表征以及本征缺陷的动力学都是重要的。阳离子和电荷载流子动力学的分析有助于对纳米晶体半导体的基本理解，以及这些有前途的材料在能源生产和储存中的应用。本课题建立了两种材料电接触的模型体系，用于载流子动力学的一般研究。

I-III-VI2 semiconductors line CuInS2 are promising materials, because they do not contain toxic heavy metals like CdSe, PbS or methylammonium lead perovskites. However, in form of nanocrystals the photo-physics if I-III-VI2 semiconductors is not yet well understood, because excited charge carriers tend to localise at intrinsic defects instead of assuming an excitonic state defined by the particle size. There exist different models for the charge carrier dynamics in I-III-VI2 semiconductors, but none of them could have been unambiguously proven or disproven. To test these models and identify the charge carrier dynamics of I-III-VI2 semiconductors the synthesis of heterostructures is proposed, in which the material under investigation shares an interface with a well-characterised, second material. The interface is chosen in such a way that the excited electrons and holes get spatially separated. This way it will be possible to quantify their contributions to the charge carrier dynamics and test the different models. Additionally, this project will yield information on the mobility of monovalent cations in the ternary compounds through the formation of the heterointerface. This quantity is important both for the fabrication and characterisation of the heterostructures and for the dynamics of the intrinsic defects. The analysis of cation and charge carrier dynamics contributes significantly to a fundamental understanding of nanocrystalline semiconductors and the technical use of these promising materials for applications in energy production and storage. The project establishes the model system of two materials in electronic contact for the general investigation of charge carrier dynamics.