Separating microstructure-related from photo-induced degradation mechanisms in NFA based organic solar cells (Project 9)

将基于 NFA 的有机太阳能电池中与微观结构相关的机制与光致降解机制分开（项目 9）

• 批准号: 511600498
• 负责人: Professor Dr. Christoph J. Brabec
• 金额: --
• 依托单位: Lehrstuhl für Materialien der Elektronik und Energietechnik
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/511600498?language=en
• 关键词: Separating; microstructure; related; photo; induced

Transition from fullerene based to non-fullerene-based acceptors (NFAs) has eliminated two major degradation processes in organic solar cells (OSCs): fullerene dimerization and fullerene diffusion. First experiments evidenced unprecedented device lifetime for selected NFA composites. P3HT:IDTBR solar cells were recently operated by our groups for over 25000 hrs continuously without obvious signs of degradation under 1 sun equivalent LED illumination and at temperatures below 40◦C. However, higher temperatures as well as UV / blue light are known to induce distinct degradation mechanisms in OSCs. Our recent investigations provided first in-sight into the mechanisms behind these degradation processes. We found a distinctly expressed wavelength dependence for photodegradation, which reached far into the 500 nm regime. More-over, we found that controlling the dimensionality and density of charge generating interfaces is a key parameter to enhanced thermal stability. Controlling the donor / NFA microstructure is of central importance to P9–Brabec/Li. Bulk heterojunction (BHJ) composites, bilayer (BL) as well as pseudo bilayer (PBL) solar cells will be made by conventional printing techniques, by layer transfer or by orthogonal solvent processing. This approach aims to control the active layer microstructure, giving us the ability to tune the device from a pure bilayer, through to an inter-diffused bilayer device and finally to an optimised bulk heterojunction in a controlled way. Thermal degradation as well as spectrally resolved photo induced degradation will be separately studied for these reference architectures and compared to the classical bulk heterojunction concept. Degradation of partially finished solar cell stacks will allow to investigate interactions between neighbouring layers and help identify the leading degradation mechanisms. Machine Learning Techniques will correlate the data from various characterization techniques as absorption, transient PL and electrical measurements to provide a predictive framework for organic photovoltaic (OPV) stability investigations. Based on the knowledge gained in this project, several strategies will be employed to mitigate thermal as well as photo-chemical degradation and to fabricate highly stable lab scale devices.

从富勒烯基受体到非富勒烯基受体（nfa）的转变消除了有机太阳能电池（OSCs）中的两个主要降解过程：富勒烯二聚化和富勒烯扩散。第一次实验证明了所选NFA复合材料的前所未有的设备寿命。P3HT:IDTBR太阳能电池最近由我们的团队在1个太阳等效LED照明和低于40℃的温度下连续运行超过25000小时，没有明显的退化迹象。然而，已知较高的温度以及紫外线/蓝光会诱导osc中不同的降解机制。我们最近的研究首次深入了解了这些降解过程背后的机制。我们发现光降解具有明显的波长依赖性，达到了500 nm的范围。此外，我们还发现控制电荷生成界面的维数和密度是提高热稳定性的关键参数。控制供体/ NFA微观结构对P9-Brabec /Li至关重要。大块异质结（BHJ）复合材料、双层（BL）以及伪双层（PBL）太阳能电池将通过传统的印刷技术、层转移或正交溶剂处理来制造。这种方法旨在控制有源层微观结构，使我们能够以可控的方式将器件从纯双层调谐到相互扩散的双层器件，并最终调谐到优化的体异质结。我们将分别研究这些参考结构的热降解和光谱分辨光诱导降解，并与经典的体异质结概念进行比较。部分完成的太阳能电池堆的退化将允许研究相邻层之间的相互作用，并有助于确定主要的退化机制。机器学习技术将把吸收、瞬态PL和电测量等各种表征技术的数据联系起来，为有机光伏（OPV）稳定性研究提供预测框架。基于在本项目中获得的知识，将采用几种策略来减轻热降解和光化学降解，并制造高度稳定的实验室规模设备。