A Paradigm Shift in Roll-to-Roll Spatial Atomic Layer Deposition for Perovskite Solar Cell Manufacture

Nowadays, Atomic Layer Deposition (ALD) is an key enabling technology in the semi-conductor manufacturing a.o. because of the atomic scale thickness control and excellent conformality in 3D structures. For large area deposition, particularly in roll-to-roll (R2R) processing, such a temporal ALD reactor is highly incompatible due to the fact that the process is operating at low pressure and exposure of precursor and co-reactant is done sequentially in time. Spatial ALD (s-ALD), however, enables parallel exposure of precursor and co-reactant operating at atmospheric pressure which makes it seamlessly compatible with R2R processing. The paradigm in R2R s-ALD consists of a rotating deposition head with the web transported floating on the process gas in counter direction along the perimeter of the deposition head. We propose a paradigm shift in R2R s-ALD. We have developed a robust R2R s-ALD solution which can operate at 100 times higher web speed. Our R&D tool can be utilized for the development of various functional inter-layers in PSCs. To boost the efficiency of PSCs high quality thin films are prerequisite and our R2R s-ALD tool can offer the highest film quality at flexible (0.05-5 m/s) deposition speeds. Several examples of functional inter-layers in PSCs will be showcased from passivation, charge transport and high performance moisture barrier layers. ᐧ