Impact of morphology on loss mechanisms in printed solar cells

该项目的双重目标是a)了解基于非富勒烯受体(NFA)的全印刷有机太阳能电池的损耗机制，以及b)利用这一了解来预测基于NFA的印刷大面积器件的最终性能。我们将关注印刷有机层的纳米形态(纳米尺度)和微观结构(μm尺度)如何影响复合产率和传输损耗，以及它最终如何影响印刷太阳能光伏器件的性能。将使用物理实验和数值模拟来支持这项工作。为了在电极沉积之前预测印刷有源层的开路电压，将开发一种“高光谱”方法，以绘制电荷转移络合物在光激励下的绝对光子发射光谱。这种解释将得到与太阳能电池表面相对应的微观2D网络模型的支持，其中每个节点都由一个完整的漂移扩散模拟组成。我们还将通过实验和3D漂移扩散模拟相结合的方式来研究纳米形态--在联盟内测量和建模--对设备物理的影响。为了更深入地理解，我们将通过测量频域中的载流子浓度和寿命来解释详细的复合损失。我们将使用漂移-扩散模型和机器学习通过全局拟合来评估实验数据，以了解限制整体器件和材料性能的瓶颈。这种方法将使我们能够详细了解不同长度尺度上的器件物理，以及这些物理过程最终如何影响大面积印刷太阳能电池的器件特性。结合Popular财团中的其他项目，我们将能够解开印刷NFA有机太阳能电池的功能-属性关系。

The dual aims of this project are to a) understand loss mechanisms in all-printed organic solar cells based on non-fullerene acceptors (NFAs), and b) to use this understanding to predict the final performance of printed large area NFA-based devices. We will focus on how the on nanomorphology (nm scale) and microstructure (μm scale) of printed organic layers affect recombination yield and transport losses, and how it ultimately impacts the performance of printed solar photovoltaic devices. Both physical experiments and numerical simulation will be used to underpin this work. A "hyperspectral" approach will be developed, to map the absolute photon emission spectra from charge transfer complexes upon optical excitation, in order to predict the open circuit voltage of printed active layers before the deposition of electrodes. The interpretation will be supported by a microscopic 2D network model, corresponding to the solar cell surface, where each node consists of a complete drift–diffusion simulation. We will also study the impact of the nanomorphology – measured and modelled within the consortium – on the device physics by a combination of experiments and 3D drift–diffusion simulations. For a deeper understanding, we will account for the detailed recombination losses by measuring charge carrier concentration and lifetime in the frequency domain. We will evaluate the experimental data by global fitting using the drift–diffusion model with machine learning to understand the bottlenecks limiting overall device and material performance. This approach will enable gaining a detailed understanding of both the device physics on different length scales, and how these physical processes ultimately affect the device characteristics of large area printed solar cells. In combination with the other projects within the POPULAR consortium, we will be able to unravel the function–property relations of printed NFA-based organic solar cells.