Enhanced resistive switching of silver copper iodide thin films prepared by interfacial phase formation

Cu cations improved the electrical and chemical performance by interfacial substitution. The photochemical stability and switching efficiency of the β′-Ag0.7Cu0.3I thin layer were enhanced compared with those of pristine AgI. We compared the electrical characteristics of the β-AgI- and β′-Ag0.7Cu0.3I-based ReRAM devices depending on the applied potential. When the currents of the devices at the high-voltage from −3 to 1 V of the sweep range were collected, both devices showed a similar I–V curve, exhibiting the characteristic of a negative differential resistance effect. Significantly, at the ± 0.1 V of the sweep range, the β-AgI-based device showed ohmic behavior. In contrast, the β′-Ag0.7Cu0.3I-based device showed excellent RS behavior with high ON/OFF ratio because its electrical property was improved via interfacial chemical modification with Cu+ cations.