A-site Modified Hybrid Perovskites: Compositional Engineering and Role of Grain Boundaries on Optoelectronic Properties (ASTRAL)

A 位改性杂化钙钛矿：成分工程和晶界对光电性能的作用 (ASTRAL)

• 批准号: 423745771
• 负责人: Professor Dr. Sanjay Mathur
• 金额: --
• 依托单位: Institut für Anorganische Chemie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/423745771?language=en
• 关键词: site; Modified; Hybrid; Perovskites; Compositional

Hybrid lead iodide perovskites based on a mixture of A-site cations have attracted significant attention due to their higher stability when compared to the parent compound methyl ammonium lead triiodide. The objectives of this project center around fundamental understanding of formability, crystallization and grain boundary engineering in solution-processed A-site modified hybrid alkyl ammonium lead iodide perovskites. Through an integrated synthesis, processing and computational effort, functional perovskite inks with optimal crystal size and solvent chemistry will be developed to examine the optoelectronic properties of solid-state absorber films in device structures. In order to understand the synergistic effect of multi-cation hybrid perovskite structures, detailed information on the role and position of the different A-site cations and crystal symmetry is critically important. Owing to the chemical and structural degrees of freedom, we propose to systematically vary the substitution of A-site cations, which are majorly responsible for the structural parameters (tolerance factor) and modulations in optical band gap The research tasks in this project will primarily focus on (i) formulation of perovskite inks based on A-site modified chemical compositions ((A1,A2,A3,A4)PbI3) in conjunction with solution studies to develop synthetic protocols for controlled crystal growth and test new solvent systems for precise crystal engineering (ii) control of on-surface grain growth and tailoring of grain boundaries in single and tandem application methods (spin-coating and electrospraying) (iii) fabrication of perovskite solid-state absorber films to investigate the transport properties as function of the size of perovskite domains (iv) detailed understanding of perovskite materials, their composition, nucleation and layer growth and effects of intergranular and intragranular transport mechanisms in predevice structures (v) demonstrate the impact of A-site engineering in mixed-cation perovskites by validating the experimental data through DFT calculations and (vi) fabricate thin film solar cell device structures and evaluation of the solvent influence, deposition technique and processing conditions on the device performance and stability. Preliminary studies on degradation of pre-device structures through light or heat-stimulated processes will be initiated as well. In summary, this interdisciplinary effort will pursue an integrated synthesis – application – modelling approach to gather new insights in the nucleation behavior of perovskite crystals with A-site variations and in-situ studies on solvent effects to obtain stable and processable inks, film formation and understanding of pre-device structure towards optical and transport properties that will be validated by DFT calculations on defect chemistry of A-site mixed systems and modelling of grain boundary transport.

基于A位阳离子的混合物的混合碘化铅钙钛矿由于其与母体化合物甲基铵三碘化铅相比更高的稳定性而引起了显著的关注。该项目的目标围绕着对溶液处理的A位改性的混合烷基铵碘化铅钙钛矿的可成形性、结晶和晶界工程的基本理解。通过综合的合成，加工和计算工作，将开发具有最佳晶体尺寸和溶剂化学的功能性钙钛矿油墨，以检查器件结构中固态吸收膜的光电性能。为了理解多阳离子混合钙钛矿结构的协同效应，关于不同A位阳离子的作用和位置以及晶体对称性的详细信息是至关重要的。由于化学和结构的自由度，我们建议系统地改变A位阳离子的取代，这是结构参数的主要原因本项目的研究任务将主要集中在（i）基于A位改性化学成分的钙钛矿油墨的配制（（A1，A2，A3，A4）PbI 3）结合溶液研究，开发用于受控晶体生长的合成方案，并测试用于精确晶体工程的新溶剂系统（ii）控制表面晶粒生长，并在单一和串联应用方法中定制晶界（旋涂和电喷雾）（iii）制造钙钛矿固态吸收膜以研究作为钙钛矿畴尺寸的函数的传输性质（iv）详细了解钙钛矿材料，它们的组成，成核和层生长以及前器件结构中的粒间和粒内传输机制的影响（v）通过DFT计算验证实验数据来证明混合阳离子钙钛矿中A位工程的影响，以及（vi）制备薄膜太阳能电池器件结构，并评估溶剂、沉积技术和工艺条件对器件性能和稳定性的影响。还将启动关于通过光或热刺激过程降解预器件结构的初步研究。总之，这一跨学科的努力将追求一种综合的合成-应用-建模方法，以收集具有A位变化的钙钛矿晶体的成核行为的新见解，并对溶剂效应进行原位研究，以获得稳定和可加工的油墨，薄膜的形成和对光学和输运性质的前器件结构的理解，这将通过对A-现场混合系统和晶界运输建模。