Dam, Henrik Friis4; Andersen, Thomas Rieks5; Pedersen, Emil Bøje Lind6; Thydén, Karl Tor Sune1; Helgesen, Martin1; Carlé, Jon Eggert1; Jørgensen, Peter Stanley1; Reinhardt, Juliane7; Søndergaard, Roar R.1; Jørgensen, Mikkel1; Bundgaard, Eva1; Krebs, Frederik C1; Andreasen, Jens Wenzel1
1 Department of Energy Conversion and Storage, Technical University of Denmark2 Functional organic materials, Department of Energy Conversion and Storage, Technical University of Denmark3 Imaging and Structural Analysis, Department of Energy Conversion and Storage, Technical University of Denmark4 Department of Micro- and Nanotechnology, Technical University of Denmark5 Risø National Laboratory for Sustainable Energy, Technical University of Denmark6 DTU Admission Course, Technical University of Denmark7 Deutsches Elektronen-Synchrotron
The realization of a complete tandem polymer solar cell under ambient conditions using only printing and coating methods on a flexible substrate results in a fully scalable process but also requires accurate control during layer formation to succeed. The serial process where the layers are added one after the other by wet processing leaves plenty of room for error and the process development calls for an analytical technique that enables 3D reconstruction of the layer stack with the possibility to probe thickness, density, and chemistry of the individual layers in the stack. The use of ptychography on a complete 12-layer solar cell stack is presented and it is shown that this technique provides the necessary insight to enable efficient development of inks and processes for the most critical layers in the tandem stack such as the recombination layer where solvent penetration in fully solution processed 12-layer stacks is critical in eleven of the steps.