Project Details
Projekt
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
Applicants
Dr. Thomas Mayer; Dr. Uli Würfel
Subject Area
Experimental Condensed Matter Physics
Term
from 2019 to 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 423746744
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.
DFG Programme
Priority Programmes
