Lamination as an Alternative Manufacturing Pathway to Realize Stable Perovskite Solar Cells

Laminated perovskite solar cells (L-PSCs) have recently been shown to be a promising alternative to traditional layer-by-layer deposition processes. In this fabrication process, two transport layer-perovskite half-stacks are independently processed and laminated at the perovskite-perovskite interface through diffusion bonding. This process overcomes chemical and thermal stability limitations during cell fabrication by eliminating any deposition steps on top of the chemically and thermally sensitive perovskites. We have recently demonstrated L-PSCs with above 21% PCE, which is uniquely enabled by a combination of inorganic transport layers and SAM passivation at both ETL and HTL interfaces.¹<br/>Here, we demonstrate the lamination of MA-free Cs_0.1FA_0.9PbI₃ PSCs for the first time, avoiding the volatile and reactive nature of the MA⁺ cation and instabilities from Br de-mixing. Laminated Cs_0.1FA_0.9PbI₃ PSCs incorporating <i>in situ</i> small-molecule passivants show a maximum efficiency of over 20.6% (average of 19.9 ± 0.6%). Additionally, lamination provides a pathway to improve stability compared to traditional fabrication processes because it results in the self-encapsulation of the perovskite layers between two substrates immediately upon finishing the device. We show that laminated devices retain 95% of their initial efficiency after 50 thermal cycles from -40^o to 85 ^oC, while maintaining a mechanical toughness after TC50 that is greater than the pristine toughness reported for layer-by-layer cells of similar efficiency. We further demonstrated improved stability under 1-sun, 85°C test conditions. These results highlight the potential of both self-encapsulation and novel passivation strategies that are enabled by the lamination process toward durable, commercially-relevant perovskite solar cells.<br/><br/>Reference<br/>1. Yadavalli, S. K. <i>et al.</i> Lamination of &gt;21% Efficient Perovskite Solar Cells with Independent Process Control of Transport Layers and Interfaces. <i>ACS Appl. Mater. Interfaces</i> <b>16</b>, 16040–16049 (2024).