Controlled synthesis and characterization of Ag2S films with varied microstructures and its role as asymmetric barrier layer in trilayer junctions with dissimilar electrodes

In this study, we examine the possibility of electrode-barrier interactions in modifying the electrical characteristics and current switching behavior of a trilayer junction with silver sulfide as the barrier layer. A series of Al–Ag2S–Ag crossbar junction is fabricated by thermal evaporation technique varying the thickness (30–110Å) of the sulfide layer. Current-voltage characteristics of the junctions are studied as a function of barrier layer thickness, which can suggest any role that electrode-barrier interaction may have in tuning their electrical behavior. To fully understand the performance of the barrier layer, structure and physical properties of Ag2S films are independently investigated. The microstructure of Ag2S films strongly depends on the deposition conditions that, in turn, affect their electrical and optical characteristics. The polarization of the lattice prevalent in Ag2S is shown to affect the charge carrier conduction in their films and dominates their electrical behavior and that of the junctions.