Mechanosynthesis of Layered Double Perovskites with Aromatic Spacer Cations for Lead‐Free Thin‐Film Opto(electro)ionics

In the quest for stable, eco-friendly, lead-free halide perovskites, layered double perovskite semiconductors are promising derivatives that remain underexploited. We demonstrate the use of mechanosynthesis to access these materials for silver(I) and bismuth(III) analogues incorporating benzylammonium and 1,4-phenylenedimethylammonium bromide cations in Ruddlesden–Popper and Dion–Jacobson phases, respectively. Their thin films were fabricated and analysed by a combination of techniques, demonstrating the potential use in thin-film opto(electro)ionics.