Composition pinning growth for efficient and stable all-inorganic Pb-Sn perovskite solar cells

초록

All-inorganic Pb-Sn perovskites offer near-optimal bandgaps for photovoltaics but suffer from compositional inhomogeneity and limited operational stability, particularly in large-area devices. Here, we demonstrate that the film formation pathway plays a decisive role in governing the optoelectronic properties and device performance of all-inorganic CsPb0.5Sn0.5I3 perovskite solar cells (PSCs). By employing a composition pinning growth (CPG) strategy, the formation of segregation-prone crystallization states is suppressed, leading to reduced surface Sn enrichment and Sn oxidation, lower defect density, and more favorable charge-carrier dynamics. As a result, CPG-based devices achieve power conversion efficiencies (PCEs) of 19.37% at the unit-cell level, among the highest of reported all-inorganic Pb-Sn PSCs, and 17.03% for 64 cm2 aperture area modules and enhanced operational stability, retaining approximately 87% of the initial efficiency after 1000 h of continuous operation at 85 degrees C and 85% relative humidity. This work establishes growth-pathway engineering as a scalable and effective strategy for achieving high-efficiency, stable all-inorganic CsPb0.5Sn0.5I3 perovskite photovoltaics.image

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