Fully Roll-to-Roll Fabricated Perovskite PV Modules with Printed Carbon Electrodes

Organic-inorganic hybrid perovskite photovoltaics (PePV) are a promising next-generation PV technology with a rapidly increasing power conversion efficiency (PCE). One of the key advantages of PePV is its solution processability. This allows PePV to be manufactured by cost-effective industrial roll-to-roll (R2R) processes. However, rapid progress in the technology has been achieved predominantly by spin coating, a laboratory process that is not compatible/transferable to the R2R process. Typically, only a small fraction of reported processes developed by spin coating are applicable in the R2R process and, therefore, a reiteration of process optimization is required for the R2R fabrication of perovskite PV. Therefore, CSIRO has been developing R2R fabrication techniques by using the R2R process since the first demonstration of R2R fabrication of PePV with 11% PCE in 2017. Since then, various fabrication techniques have been developed and PCEs have been improving. However, the devices, even those that claim to be fully R2R processed PePV cells, have been fabricated using vacuum deposition techniques for the deposition of metal back electrodes. Vacuum deposition is a costly process and it is not feasible to integrate it into a conventional printing line. Therefore, the creation of R2R-printable back electrodes has been identified as a key obstacle for the low-cost R2R manufacturing of large-area PePV. Therefore, CSIRO, in partnership with Monash University, University of New South Wales and the University of Cambridge, addressed this challenge and developed R2R printable electrode materials. This work resulted in the first R2R production of fully printed PePV modules. Perovskite formulations and R2R deposition techniques have also been further developed and enabled up to 18 % PCE from flexible R2R devices with vacuum electrodes. Fully R2R processed cells, with carbon electrodes and printed silver grids, showed over 14 % PCE. The process has been used in industrial R2R printers to demonstrate >10 % PCE from 10 cm x 10 cm from R2R printed flexible modules. An overview of the collaboration project will be presented in the presentation