Researchers from the Center for Solar Energy and Hydrogen Research Baden-Württemberg in Germany, the University of Munich (LMU) and Newcastle University in the UK have developed a practical tool for solution-based perovskite processing.
The team developed a unique method based on the deposition of size-controlled Al2O3 or SiO2 nanoparticles. By enhancing the surface energy, they act as a universal wetting agent. This allows perovskite precursor solutions to be spread evenly over various substrates, including problematic hydrophobic Si-wafers or fullerene self-assembled monolayers (C60-SAMs).
The researchers also reported that the perovskite morphology, solar cell performance, and reproducibility benefit from the presence of the nanoparticles at the interface. When applied to 144 cm2 C60-SAM-coated substrates, homogeneous coverage can be realized via spin coating resulting in average efficiencies of 16% (maximum 18%) on individualized cells with 0.1 cm2 active area. Modules in the same setup reached maximum efficiencies of 11 and 7% on 2.8 and 23.65 cm2 aperture areas, respectively.