Interfacial coordination utilizing chelating ligands for operationally stable perovskite solar modules

Abstract

Perovskite solar cells (PSCs) feature a higher maximum theoretical efficiency and a lower cost than silicon-based solar cells, while also offering additional advantages of being flexible and transparent. However, the commercialization of PSCs remains a great challenge due to rapidly degraded efficiency and stability when scaled up to industrial sizes. Here, we develop an interfacial coordination strategy utilizing chelating ligands to address both the efficiency and stability issues on a large scale. The ligands can form a layer of Pb(II) coordination polymers with robust chemical bonds that not only effectively passivate surface defects but also serve as a tightly adhered capping layer for protecting the perovskite surfaces. Then, the as-fabricated solar module with an area of up to 31.6 cm² exhibits a projected T₈₀ lifetime of over 9000 hours under 1-sun illumination at 25 °C. Moreover, the ligands introduce suitable energy levels between the perovskite and electron charge transport layer to facilitate charge transfer across the interface. As a result, we simultaneously achieve a power conversion efficiency of 25.0% for a 0.16 cm² single cell, and 22.6% for a 31.6 cm² module, comparable to the efficiencies achieved by state-of-the-art solar modules of similar sizes.