Single-Source Pulsed Laser Deposited Perovskite Solar Cells with >19% Efficiency

Abstract Single-source vapor deposition of metal halide perovskites has, to date, remained challenging due to the dissimilar volatilities of the perovskite precursors, limiting the controlled transfer of multiple elements at once. Here, we demonstrate that pulsed laser deposition (PLD) addresses the rate-control challenges of single-source evaporation, enabling solar cells with power conversion efficiencies above 19%. We combined dry mechanochemical synthesis and PLD to fabricate MA1-xFAxPbI3 and Cl-passivated MA1-xFAxPbI3 films from a single-source target. The films are grown onto hole-selective self-assembled monolayers, where first a thin PbI2-rich layer forms, leading to full perovskite conversion. Onto the perovskite, an oleylammonium iodide (OAmI) post-treatment is then applied to passivate its top surface by forming a 2D perovskite film. When incorporating PbCl2 in the target and OAmI-based 2D passivation, a remarkable 19.7% efficiency for p–i–n perovskite solar cells is achieved with enhanced device stability. This highlights the appeal of PLD to fully unlock the potential of single-source vapor-deposited perovskite towards low-cost and efficient photovoltaics.