Tautomeric Metal-Polymer Coordination Enables Damage-Free Laminated Carbon Electrodes in Inverted Perovskite Solar Cells

Abstract

Abstract Integrating dry carbon electrodes (CEs) into inverted perovskite solar cells (PSCs) offers a solvent-free, scalable route to low-cost photovoltaics. However, mechanical stress during lamination and the large work-function mismatch between the CE and the electron transport layer (ETL) can compromise performance. Here, we report an interface engineering strategy utilizing a silver-2-mercaptobenzothiazole (Ag-MBT) metal-polymer buffer layer to enable high-efficiency inverted CE-based PSCs (C-PSCs). XPS reveals Ag-induced changes in the sulfur and nitrogen chemical environments of MBT, consistent with the formation of an Ag-MBT interfacial coordination layer involving Ag–S coordination. This coordination-derived interlayer serves a dual function: it acts as a structural buffer, enabling damage-free dry CE lamination, and it establishes an energetic band alignment that bridges the ETL/CE work-function gap. Consequently, our devices achieve a champion power conversion efficiency (PCE) of 20.12% and maintain their initial efficiency after 1000 h of dark N2 storage, establishing metal-polymer interfacial coordination as a viable pathway for robust inverted C-PSCs.