Plasma Polymer Passivation of Perovskite Solar Cells for Improved Stability and Reproducibility

Hybrid halide perovskite solar cells, despite their relatively recent development, have achieved efficiencies comparable to commercial silicon-based technologies and have surpassed those of quantum-dot solar cells. However, their scalability is hindered by issues related to reproducibility and stability under environmental conditions. Current approaches to improve these challenges often involve solvent-based methods, which complicate industrial scalability. In this study, we present an alternative approach by introducing an ultrathin plasma polymer as a passivation interface between the electron transport layer and the hybrid perovskite layer, synthesized by remote plasma-assisted vacuum deposition (RPAVD) at room temperature.[1,2] This nanoengineered interface enhances the long-term stability of the solar cells under ambient conditions, allowing them to retain over 80% of their initial efficiency after more than 1000 hours of exposure. Without requiring additional encapsulation steps, this method also improves the coverage of the mesoporous scaffold by the perovskite layer, resulting in enhanced device performance. A champion efficiency of 19.2% is achieved, a notable improvement for Li-free standard mesoporous n-i-p architectures, along with significant gains in reproducibility.[3]
Additionally, we have demonstrated that the same plasma polymer material can be used as an encapsulant in the final step, offering water protection while also serving as a nanometric interface coating to enhance cell performance.[4] The dual functionality of this material as both a protective encapsulant and an interface layer represents a practical advantage, potentially accelerating the pathway to industrial-scale production of perovskite solar cells.
[1] M. Alcaire, et al., Adv. Funct. Mater. 29, 2019, 1903535 DOI 10.1002/adfm.201903535
[2] F. Carrascoso, et al., npj 2D Mater. Appl. 7, 2024, 24 DOI 10.1038/s41699-023-00393-1
[3] J.M. Obrero, et al. Adv. Energy Mater. 12, 2022, 2200812 DOI 10.1002/aenm.202200812
[4] J. Idígoras, et al., ACS Appl. Mater. Interfaces 10, 2018, 11587 DOI 10.1021/acsami.7b17824