Pushing the FF of Non-Fullerene Acceptors Based Solar Cells Above 80%: Relating Order to Reduced Recombination to Device Performance

推动%20the%20FF%20of%20Non-Fullerene%20Acceptors%20Based%20Solar%20Cells%20Above%2080%:%20Related%20Order%20to%20Reduced%20Recombination%20to%20Device%20Performance

• 批准号: 450968074
• 负责人: Professor Dr. Dieter Neher
• 金额: --
• 依托单位: Institut für Physik und Astronomie
• 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/450968074?language=en
• 关键词: Pushing; FF; Non; Fullerene; Acceptors

Recent advances in organic bulk heterojunction solar cells, enabled in particular by the recent development of non-fullerene acceptors (NFAs), have led to large improvements in the power conversion efficiency, with current leading certified efficiencies of 17.6% for single-junction devices. As an important photovoltaic parameter, the fill factor (FF) of OSCs stands for the electric field dependence of free charge generation and extraction in competition to geminate and non-geminate losses. However, the FF values of such high efficiency cells still lie well below the Shockley-Queisser limit. Therefore, the overreaching goal of this project is to push the FF of highly-efficient organic solar cells by investigating and understanding the particular roles that crystallinity and miscibility of the donor and the acceptor in the photoactive layer have on the processes determining the JV-characteristics. Hereby, we will focus on the detailed investigation of the transport and recombination of free photogenerated carriers in relation to structural and energetic properties of the multicomponent blend layer. To this end, we will employ various techniques established at Potsdam University such as T-dependent space charge limited currents, resistive photovoltage, time-delayed collection field and photoinduced absorption to arrive at a conclusive picture of the charge carrier dynamics. These studies will be performed on a series of blends based on Y-type NFAs, which are chosen for their particular chemical and structural characteristics. Results from these experimental investigations will serve as input to numerical simulations to confirm the role of bulk and surface recombination and how they determine primarily the FF but also the VOC. By doing so, we aim at identifying the criteria which needs to be met to realize, simultaneously, efficient charge extraction and highly suppressed (non-Langevin) recombination, and to push the FF of these devices reliably above 80%.

有机本体异质结太阳能电池的最新进展，特别是通过非富勒烯受体（NFA）的最新发展，已经导致功率转换效率的大幅提高，目前单结器件的认证效率为17.6%。作为一个重要的光伏参数，OSC的填充因子（FF）代表了自由电荷的产生和提取对成对和非成对损失的竞争的电场依赖性。然而，这种高效率电池的FF值仍然远低于Shockley-Queisser极限。因此，本项目的超越目标是通过研究和理解光活性层中供体和受体的结晶度和可结晶性对决定JV特性的过程的特定作用来推动高效有机太阳能电池的FF。因此，我们将集中在自由光生载流子的传输和重组的多组分共混层的结构和能量特性的详细调查。为此，我们将采用在波茨坦大学建立的各种技术，如T依赖的空间电荷限制电流，电阻光伏，时间延迟收集场和光致吸收到达一个结论性的图片的载流子动力学。这些研究将在一系列基于Y型NFA的共混物上进行，这些共混物是根据其特定的化学和结构特征选择的。这些实验研究的结果将作为数值模拟的输入，以确认体相和表面复合的作用，以及它们如何主要确定FF和VOC。通过这样做，我们的目标是确定需要满足的标准，以同时实现有效的电荷提取和高度抑制的（非朗之万）复合，并将这些器件的FF可靠地推到80%以上。