Mechanosynthesis of Metal‐Free Molecular Perovskites

Metal-free halide perovskites have recently emerged as promising candidates for optoelectronic applications. However, their synthesis has largely depended on water-based single-crystal growth that limits material diversity, scalability, and practical implementation. Here, we present a mechanochemical route to synthesize N,N-diazabicyclo[2.2.2]octonium (H-DABCO)-based halide perovskites from the (DABCO)(NH4)X3 (X = I, Br) compositions. The structural properties were confirmed by X-ray diffraction and solid-state nuclear magnetic resonance spectroscopy. Thin films were prepared from mechanosynthetic powders by spin-coating and characterized by in-situ grazing incidence wide-angle scattering measurements, as well as by UV–vis absorption and steady-state photoluminescence spectroscopy. This mechanosynthetic strategy provides a scalable, environmentally friendly pathway to broaden the scope of metal-free perovskites and advance their potential in sustainable optoelectronic technologies.