A two-dimensional lead-free hybrid perovskite semiconductor with reduced melting temperature.

1-Methylhexylammonium tin iodide yields the lowest reported melting temperature (Tm = 142 °C) to date among lead-free hybrid perovskite semiconductors. Molecular branching near the organic ammonium group coupled with tuning of metal/halogen character suppresses Tm and facilitates effective melt-based deposition of films with 568 nm absorption onset.