Interface-controlled Ag2O-Si wafer heterojunctions showing current rectification and light-responsive conductivity

Abstract

To investigate the presence of current rectification behavior in facet-controlled Ag2O/Si heterostructures, Ag2O cubes, octahedra, and rhombic dodecahedra exposing respective {100}, {111}, and {110} surfaces were synthesized. Their I-V curves were collected using a conductive atomic force microscope (AFM). While all the Ag2O polyhedra exhibited high conductivity responses, octahedra were particularly conductive. Conductivity measurements were also performed on Si {100}, {111}, and {110} wafers, showing Si {111} wafer to be most conductive. Subsequently, these Ag2O polyhedra were added to different silicon wafers for electrical conductivity measurements by making electrical connection to the heterostructures. Ag2O octahedron/Si {100} wafer and rhombic dodecahedron/Si {110} wafer cases exhibited the best and clean current-rectifying behavior. Under white light-emitting diode (LED) illumination, Ag2O octahedron/Si {100} wafer, cube/Si {111} wafer, and 2 rhombic dodecahedron/Si {111} wafer combinations showed significant photocurrent enhancement for photodetector application. Thus, by controlling the contacting crystal faces in semiconductor heterojunctions, it is possible to utilize the semiconductor facet effects to fabricate novel transistors, especially if the top semiconductor can be made by a solution approach to incorporate into the chip manufacturing process.