Solid state devices based upon Cu2O were found to exhibit different current–voltage (I–V) relationships. The usual interpretation of these I–V relationships was to assume that Schottky barriers existed between a metal electrode and the oxide. A new form of I–V relationship was reported here for devices based upon thin films of Cu2O. Their interpretation called for mixed ionic-electronic conduction in the oxide. The ionic conductivity, although low, was sufficient to permit redistribution of the native acceptors over the time-scale of the measurements.

Solid State Devices Based on Thin Films of Cu2O Show a New Type of I–V Relation. Z.Rosenstock, I.Feldman, I.Riess: Solid State Ionics, 2004, 175[1-4], 375-8