Efficient Defect-Driven Cation Exchange beyond the\nNanoscale Semiconductors toward Antibacterial Functionalization

Defect engineering is an exciting tool for customizing\nsemiconductors’\nstructural and optoelectronic properties. Elaborating programmable\nmethodologies to circumvent energy constraints in multievent inversions\nexpands our understanding of the mechanisms governing the functionalization\nof nanomaterials. Herein, we introduce a novel strategy based on defect\nincorporation and solution rationalization, which triggers energetically\nunfavorable cation exchange reactions in extended solids. Using Sb<sub>2</sub>X<sub>3</sub> + Ag (I) → Ag: Sb<sub>2</sub>X<sub>3</sub> (X= S, Se) as a system to model, we demonstrate that incorporating\nchalcogen vacancies and Ag<sub>Sb</sub>V<sub>X</sub> complex defects\ninto initial thin films (TFs) is crucial for activating long-range\nsolid-state ion diffusion. Additional regulation of the Lewis acidity\nof auxiliary chemicals provides an exceptional conversion yield of\nthe Ag precursor into a solid-state product up to 90%, simultaneously\ntransforming upper matrix layers into AgSbX<sub>2</sub>. The proposed\nstrategy enables tailoring radiative recombination processes, offers\nefficiency to invert TFs at moderate temperatures quickly, and yields\nstructures of large areas with substantial antibacterial activity\nin visible light for a particular inversion system. Similar customization\ncan be applied to most sulfides/selenides with controlled reaction\nyields.