Recent progress in nanostructured silver sulfide: from synthesis and nonstoichiometry to properties

Abstract

The microstructure (composition, nonstoichiometry, size and shape of particles) of nanostructured semiconductor silver sulfide (Ag₂S) determines its electronic structure, optical and electrical properties, and possible applications of Ag₂S in modern electronics, biology and medicine. This critical review summarizes recent progress in the design of different forms of nanostructured Ag₂S from nanopowders to colloidal solutions, quantum dots and heteronanostructures. Main results on the synthesis, structural features and properties of nanostructured Ag₂S are detailed. The appearance of nonstoichiometry in silver sublattices of monoclinic Ag₂S at decreasing size particles to the nanometer scale is considered. The interdependent changes in nonstoichiometry and crystal structure at the transformation of a nonconducting nanocrystalline Ag₂S in superionic conductors are discussed. The effects of nanocrystalline state on the peculiarities of crystal structure, nonstoichiometry, optical and thermal properties of semiconductor Ag₂S are considered. Special attention is paid to manifold applications of Ag₂S-based nanomaterials and heteronanostructures in biomarkers, resistance-switches and nonvolatile memory devices.