Controlled synthesis and characterization of Ag_2S films with varied microstructures and its role as asymmetric barrier layer in trilayer junctions with dissimilar electrodes

摘要

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-Ag_2S-Ag crossbar junction is fabricated by thermal evaporation technique varying the thickness (30-110 A) 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 Ag_2S films are independently investigated. The microstructure of Ag_2S films strongly depends on the deposition conditions that, in turn, affect their electrical and optical characteristics. The polarization of the lattice prevalent in Ag_2S is shown to affect the charge carrier conduction in their films and dominates their electrical behavior and that of the junctions.