Diode‐Like Property of Prussian Blue Films Containing Concentration Gradients in Serial Mixed Valent Layers

Abstract

Solid‐state diode‐like current‐voltage behavior is described for films of partially dried Prussian blue that contain serially arranged layers of the mixed valent states and , that contain concentration gradients of the two redox couples. The films were electrochemically grown and disproportionated to prepare the mixed valent concentration gradient microstructure. The diode‐like behavior is based on the junction between the concentration gradients of the two redox couples, where the conductive reaction, , occurs under forward bias, but its reverse is nonconductive under reverse voltage bias. Unfortunately, apparently due to uncontrolled counterion migration, the junction is not stable under reverse bias, but the Prussian blue microstructure does serve to illustrate the generality of the principle that solid‐state diode‐like junctions can be assembled from two‐couple redox materials.