Formation of Thin Films of Organic–Inorganic Perovskites for High‐Efficiency Solar Cells

TLDR

Organic‑inorganic perovskites are a leading photovoltaic material with laboratory‑scale efficiencies rivaling established thin‑film technologies, and improving film quality is key to further progress. The review aims to elucidate film‑formation techniques, the influence of solvents, precursors, and chloride ions on mixed‑halide perovskites, and to identify material properties and morphologies that enable high‑efficiency solar cells. The authors examine solvent‑ and precursor‑based film‑formation methods and their impact on crystallization and morphology to achieve high‑efficiency perovskite solar cells.

Abstract

Organic-inorganic perovskites are currently one of the hottest topics in photovoltaic (PV) research, with power conversion efficiencies (PCEs) of cells on a laboratory scale already competing with those of established thin-film PV technologies. Most enhancements have been achieved by improving the quality of the perovskite films, suggesting that the optimization of film formation and crystallization is of paramount importance for further advances. Here, we review the various techniques for film formation and the role of the solvents and precursors in the processes. We address the role chloride ions play in film formation of mixed-halide perovskites, which is an outstanding question in the field. We highlight the material properties that are essential for high-efficiency operation of solar cells, and identify how further improved morphologies might be achieved.