Achievement of two logical states through a polymer/silicon interface for organic-inorganic hybrid memory

Abstract

A hysteresis loop of minority carrier lifetime vs voltage is found in polystyrenesulfonate (PSS)/Si organic-inorganic hybrid heterojunctions, implying an interfacial memory effect. Capacitance-voltage and conductance-voltage hysteresis loops are observed and reveal a memory window. A switchable interface state, which can be controlled by charge transfer based on an electrochemical oxidation/deoxidation process, is suggested to be responsible for this hysteresis effect. We perform first-principle total-energy calculations on the influence of external electric fields and electrons or holes, which are injected into interface states on the adsorption energy of PSS on Si. It is demonstrated that the dependence of the interface adsorption energy difference on the electric field is the origin of this two-state switching. These results offer a concept of organic-inorganic hybrid interface memory being optically or electrically readable, low-cost, and compatible with the flexible organic electronics.