Electrical Switching and Memory Phenomena in Semiconducting Organic Charge-Transfer Complexes

Abstract

The observation of electrical switching and memory phenomena is known to exist in a wide variety of inorganic semiconducting thin films. These inorganic materials include the metal oxides of nickel, silicon, aluminum, titanium, zirconium, and tantalum, all of which exhibit a voltage controlled negative resistance when arranged in a metal-oxide-metal sandwich structure.1,2 The mechanism of switching is believed to be due to a forming process. The electrical behavior of these materials is not stable, reproducible, or independent of polarity. The amorphous alloys, including chalcogenide glasses, are inorganic semiconductors which also show switching behavior. These glasses contain up to four elements often including arsenic and/or tellurium and exhibit a current-controlled negative resistance. A typical example of an amorphous alloy which exhibits switching behavior is Te40As35Ge6Si18.3 These materials have been extensively investigated and the mechanism of conduction and switching is believed to be due to filaments which are described by both thermal and electronic models.