Phenothiazine-based self-assembled monolayer with thiophene head groups minimizes buried interface losses in tin perovskite solar cells

Valerio Stacchini; Madineh Rastgoo; Mantas Marčinskas; Chiara Frasca; Kazuki Morita; Lennart Frohloff; Antonella Treglia; Thomas W Gries; Orestis Karalis; Vytautas Getautis; Florian Ruske; Annamaria Petrozza; Norbert Koch; Hannes Hempel; Tadas Malinauskas; Antonio Abate; Artem Musiienko

doi:10.1002/aenm.202500841

Title	Phenothiazine-based self-assembled monolayer with thiophene head groups minimizes buried interface losses in tin perovskite solar cells
Authors	Stacchini, Valerio ; Rastgoo, Madineh ; Marčinskas, Mantas ; Frasca, Chiara ; Morita, Kazuki ; Frohloff, Lennart ; Treglia, Antonella ; Gries, Thomas W ; Karalis, Orestis ; Getautis, Vytautas ; Ruske, Florian ; Petrozza, Annamaria ; Koch, Norbert ; Hempel, Hannes ; Malinauskas, Tadas ; Abate, Antonio ; Musiienko, Artem
DOI	10.1002/aenm.202500841
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Is Part of	Advanced energy materials.. Weinheim : Wiley-VCH. 2025, vol. 15, iss. 29, art. no. 2500841, p. 1-8.. ISSN 1614-6832. eISSN 1614-6840
Keywords [eng]	buried Interface ; DMSO-free ; lead-free ; phenothiazine ; self-assembled monolayers ; solar cells ; tin perovskite
Abstract [eng]	Self-assembled monolayers (SAMs) have revolutionized the fabrication of lead-based perovskite solar cells, but they still remain underexplored in tin perovskite systems. To date, PEDOT remains the most effective hole-selective layer in tin perovskite solar cells (TPSCs), yet it presents challenges for both performance and stability. MeO-2PACz, the only SAM reported for tin perovskites consistently underperforms when compared to PEDOT. In this work, it is identified that MeO-2PACz's limitations stem from excessively strong interactions with the perovskite surface and poor lattice matching, which leads to inferior interface quality. To address these issues, a novel SAM-forming molecule called Th-2EPT is designed, synthesized, and characterized. Density functional theory (DFT) is used to evaluate coordination strength and lattice compatibility, complemented by electro-optical characterisation techniques that show significantly reduced interfacial recombination and improve material crystallinity in Th-2EPT/Perovskite films. With Th-2EPT, the first SAM-based tin perovskite solar cells that outperform PEDOT-based devices, delivering a power conversion efficiency (PCE) of 8.2% with a DMSO-free solvent system, are demonstrated.
Published	Weinheim : Wiley-VCH
Type	Journal article
Language	English
Publication date	2025
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„Phenothiazine-based self-assembled monolayer with thiophene head groups minimizes buried interface losses in tin perovskite solar cells“