Novel Cation-substituted Quarternary Chalcogenide Nanocrystals Cu2XSnS4 (X = Zn, Ni, Fe, Co): Properties and Potential Applications

新型阳离子取代季硫族化物纳米晶体 Cu2XSnS4（X = Zn、Ni、Fe、Co）：特性和潜在应用

• 批准号: 517869265
• 负责人: Professor Dr. Dietrich R. T. Zahn
• 金额: --
• 依托单位: Lashkaryov Institute of Semiconductor Physics
• 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/517869265?language=en
• 关键词: Novel; Cation; substituted; Quarternary; Chalcogenide

Cu2ZnSn(S,Se)4 (CZTSSe) has been intensively studied over the last decade as a promising alternative material for photovoltaics. However, bringing it to real-life applications is challenged by its high tolerance to non-stoichiometry, defects, and secondary phases. Substitution of cations in the CZTSSe structure showed great promise in overcoming these challenges and enabling new properties. Ag and Ba are the substituents mostly studied so far, but they cause only a partial amendment of the photovoltaic and other properties. The very interesting iron group of elements (Fe, Ni, Co) are rather unexplored in this respect yet. Systematic investigations are especially lacking for colloidal nanocrystals (NCs) of the Cu2XSnS4 (X = Zn, Ni, Fe, Co) compounds, although such NCs are a promising option for forming energy conversion and storage devices on deliberate substrates and areas by printing. The successful synthesis of CZTSSe NCs, and to a lesser extent of other I2-II-IV-VI4 NCs, has been reported. Advancing these NCs to solar cells, thermoelectrics, catalysis, and other application at a competitive level demands filling the gap in the knowledge about their structure and electronic properties. The aim of the project is to establish the relation between the lattice structure (including defects), distribution of electronic states, and optical spectra of Cu2XSnS4 (X = Zn, Ni, Fe, Co) NCs. We expect that the cation substitutions proposed in this project can (i) lead to an improvement of the properties of the host material due to the passivation of certain defects, (ii) help to establish the origin of certain native defects or electronic states in CZTS itself, and (iii) induce new properties, not existing in CZTS crystals and NCs, in particular magnetic properties. Computational screening will be performed to facilitate the synthetic part, enabling us to focus on the most promising CXTS compositions and to understand the changes in the electronic, optical, and phonon experimental spectra caused by cationic substitution. Furthermore, we will investigate the evolution of the material properties from the ensembles of as-synthesized individual NCs to polycrystalline films formed by annealing. Based on the results obtained, we will perform a preliminary investigation of the obtained material in simple photovoltaic or thermoelectric devices. In 16 years of successful collaboration between the applicants, as confirmed by more than 100 joint publications and most of them related to colloidal chalcogenide NCs, we have acquired sufficient experience and instrumental tools for the successful fulfillment of the current project. Besides established characterisation techniques, selected for the project, rather exclusive methods of deep level spectroscopies and electron paramagnetic resonance, which are available for the Ukrainian partners, are indispensable for building the complete picture of electronic states in such a complex materials as Cu2XSnS4 NCs.

近十年来，铜锌锡(S，Se)4(CZTSSe)作为一种很有前途的光伏替代材料得到了广泛的研究。然而，将其应用到现实生活中是一个挑战，因为它对非化学计量比、缺陷和第二相具有很高的容忍度。取代CZTSSe结构中的阳离子在克服这些挑战和实现新的性能方面显示出巨大的前景。到目前为止，研究最多的是Ag和Ba，但它们对光伏等性质的影响很小。非常有趣的铁族元素(铁、镍、钴)在这方面还没有被探索过。对于Cu2XSnS4(X=Zn，Ni，Fe，Co)化合物的胶体纳米晶(NCs)的系统研究尤其缺乏，尽管这种NCs是一种很有前途的选择，可以通过印刷在有意的衬底和区域上形成能量转换和存储设备。已有报道成功地合成了CZTSSe NCS，以及少量的其他I2-II-IV-VI4 NCS。在具有竞争力的水平上推动这些纳米碳管应用于太阳能电池、热电、催化和其他应用，需要填补关于它们的结构和电子性质的知识空白。本项目的目的是建立Cu2XSnS4(X=Zn，Ni，Fe，Co)NCS的晶格结构(包括缺陷)、电子态分布和光谱之间的关系。我们希望本项目中提出的阳离子取代可以(I)由于某些缺陷的钝化而导致主体材料的性质的改善，(Ii)有助于确定CZTS本身中某些本征缺陷或电子态的来源，以及(Iii)诱导CZTS晶体和NCS中不存在的新的性质，特别是磁性。将进行计算筛选以促进合成部分，使我们能够专注于最有希望的CXTS组成，并了解阳离子取代引起的电子、光学和声子实验光谱的变化。此外，我们还将研究材料性质的演变，从合成的单个纳米碳管到通过退火形成的多晶薄膜。基于所获得的结果，我们将在简单的光伏或热电器件中对所获得的材料进行初步的研究。在申请者之间16年的成功合作中，正如100多份联合出版物所证实的那样，其中大多数与胶体硫化物NC有关，我们已经为成功完成本项目获得了足够的经验和工具。除了为该项目选择的既定表征技术外，乌克兰合作伙伴可以使用的相当独特的深能级光谱和电子顺磁共振方法，对于建立Cu2XSnS4 NCS等复杂材料的电子态全景图是必不可少的。