Interrogate: Interfaces in perovskite solar cells investigated with photoelectron spectroscopy and modelling: Feed Back Loop of Full Device Fabrication, Full Device Photoelectron spectroscopy Operando Characterization, and Full Device Modeling

该项目旨在更深入地了解钙钛矿太阳能电池中钙钛矿吸收剂与电子和空穴输运材料之间的界面的影响。为此，我们汇集了我们在表征和数值器件模拟方面的专业知识。先进的全器件锥形截面光电子能谱（达姆施塔特工业大学，托马斯梅耶）将与不同的表征技术相结合，如电流电压特性，光和电致发光光谱，瞬态光致发光和太阳- voc（弗莱堡大学，Uli w<e:1> rfel）。利用新开发的全器件锥形截面光电子能谱（FDTCS-PES, Thomas Mayer）方法，我们利用小角度（0.02°）将深度剖面的nm尺度转换为锥形截面的mm尺度，并在这些锥形截面上进行XPS线扫描，步宽为50µm。电子特性的分布可以直接在锥形截面上测量。这些测量将分别在具有不同电子和空穴传输层的许多设备（如上所述在弗莱堡大学制造和表征）上进行。实验工作将辅以数值装置模拟（Freiburg大学，Uli w<e:1> rfel），以便从完整装置模型的角度确定所有实验数据的适当定量描述。将特别强调上述接口的影响。这将能够建立一个有意义的假设，该假设将在基于合理和系统的参数变化的额外实验中得到验证或证伪。在合作伙伴的实验室进行的特性描述和设备模型的改进之间的持续反馈循环将使工作计划的成功实施成为可能，并实现对接口如何限制设备性能和稳定性的更好理解，并确定克服这些挑战的方法。因此，我们将获得有关工作装置中的化学成分和电位分布的最有价值的信息。这将通过调整带隙、复合系数、陷阱态的密度和能量分布以及移动离子/离子空位浓度等参数在数值装置模拟中实现。

The proposed project aims at achieving a deeper understanding of the impact of interfaces between perovskite absorber and electron and hole transport materials in perovskite solar cells. To this end, we bring together our expertise in characterization and numerical device simulations. Advanced photoelectron spectroscopy on full device tapered cross sections (Technical University of Darmstadt, Thomas Mayer) will be combined with different characterizations techniques such as current-voltage characteristics, photo- and electroluminescence spectroscopy, transient photoluminescence and Suns-VOC (University of Freiburg, Uli Würfel). With the newly developed method full device tapered cross section photoelectron spectroscopy (FDTCS-PES, Thomas Mayer) we transfer the nm scale of the depth profile to the mm scale of the tapered cross section by using a small angle of (0.02°) and XPS line scans on these tapered cross sections are performed with step width of 50µm. The profile of electronic properties can be measured directly on the tapered cross section. These measurements will be performed on a number of devices (fabricated and characterized as mentioned above at the University of Freiburg) with different electron and hole transport layers, respectively.The experimental work will be complemented by numerical device simulations (University of Freiburg, Uli Würfel) in order to identify an appropriate quantitative description of all experimental data from the view-point of a full device model. Particular emphasis will be placed on the impact of the above mentioned interfaces. This shall enable to set up a meaningful hypothesis which will be verified or falsified in additional experiments based on rational and systematic parameter variation. This continuous feedback loop between the characterizations carried out at the labs of both partners and the refinement of the device model will enable the successful implementation of the work programme and to realize an improved understanding of how interfaces limit device performance and stability and identify ways to overcome these challenges.Thus, we will obtain most valuable information about chemical composition and the potential distribution in the working device. This will be implemented in the numerical device simulations by adjusting parameters such as band-gap, recombination coefficient and the density and energetic distribution of trap states and mobile ion/ion vacancy concentrations.