A promising approach towards highly efficient and stable large-area ITO-free perovskite solar cells is demonstrated by employing thiol-functionalized self-assembled monolayers as interfacial modification layers.
A long-term thermally stable, inexpensively produced, inorganic-hole extraction layer (i-HEL) is the best choice for the commercialization of air-thermo-stable, low-cost, highly-efficient perovskite solar cells (PSCs).