One-Pot Synthesis of Crystalline Ag2S Nanoparticles Embedded inside Amorphous Cu2S Matrix for High Electrical Conductivity

Amorphous materials exhibit distinct physical and chemical properties compared to crystalline or quasi-crystalline phases, because of their unique atomic arrangements of short-range order but long-range disorder. Designing a nanocomposite that contains both crystalline and amorphous phases is a valid approach to fully exploit the effects of each component. In this work, a nanocomposite consisting of crystalline Ag2S nanoparticles embedded in an amorphous Cu2S matrix (Ag2S/a-Cu2S) is synthesized by a facile one-pot solvothermal method. This process is achieved by diffusing silver into crystalline Cu2S. The silver is able to diffuse into Cu2S and form crystalline Ag2S nanoparticles inside them, while the crystalline Cu2S is converted into an amorphous phase owing to the silver diffusion. Furthermore, the introduction of nanoscale Ag2S particles into Cu2S improve electrical conductivity. This design of amorphous matrix containing nanocrystalline particles may open up new strategies for the transition from crystalline to amorphous phases of semiconductors.