biostudies-literatureChan PFResearch Grants Council of Hong KongNational Natural Science Foundation of Chinae06340https://www.ebi.ac.uk/biostudies/studies/S-EPMC12508707biostudies-literatureUnknown21(40)Addressing the inherent instability of tin-based perovskite solar cells (PSCs), a facile approach is introduced to simultaneously enhance their stability and performance. This study demonstrates the implementation of an ultra-thin (≈3 nm) dual-functional lead sulfide (PbS) capping layer, formed via a sequential deposition. This PbS layer serves a critical dual role: first, as a robust protective barrier against oxidation and moisture, effectively mitigating the degradation of the underlying tin-based perovskite; and second, by improving interfacial electronic properties to facilitate efficient charge extraction. Specifically, the PbS layer not only provides conformal coverage and minimizes non-radiative recombination but also acts as an n-type interfacial layer, promoting electron transporSmall (Weinheim an der Bergstrasse, Germany)Ultra-Thin Lead Sulfide Capping for Stabilizing Tin Halide Perovskite Solar Cells.PMC125087071430572152122004Zhao NWu JSu CJLu XChan PFZhang HLin JMLuo YWang XCheng HfalseUltra-Thin Lead Sulfide Capping for Stabilizing Tin Halide Perovskite Solar Cells.Addressing the inherent instability of tin-based perovskite solar cells (PSCs), a facile approach is introduced to simultaneously enhance their stability and performance. This study demonstrates the implementation of an ultra-thin (≈3 nm) dual-functional lead sulfide (PbS) capping layer, formed via a sequential deposition. This PbS layer serves a critical dual role: first, as a robust protective barrier against oxidation and moisture, effectively mitigating the degradation of the underlying tin-based perovskite; and second, by improving interfacial electronic properties to facilitate efficient charge extraction. Specifically, the PbS layer not only provides conformal coverage and minimizes non-radiative recombination but also acts as an n-type interfacial layer, promoting electron transpor2025-01-01T00:00:00Z2025 Oct2026-06-04T08:54:12.589Z2026-05-07T03:12:49.356ZS-EPMC125087074084784810.1002/smll.202506340