Multifunctional Controllable Two-Terminal Vertical Nonvolatile Memory Transistor

An electrically, magnetically, and temperature controllable two-terminal nonvolatile memory transistor with a vertical topology has been designed, fabricated, and demonstrated. This intriguing memory transistor is composed of a nonvolatile resistive random-access memory (RRAM) of the layered structure of indium–tin oxide/poly­(methyl methacrylate)/Ag in tandem with a micropyramid-structured magneto-electric film supported by a 150 μm thick partition. The magneto-electric film is made of FeNi (or CrO₂)/polydimethylsiloxane composite covered with silver nanowires and can be brought in contact with the top Ag electrode of the RRAM, forming a magneto-electric device through applying an appropriate magnetic field strength. The output current of the proposed device can be regulated when the electric voltage and magnetic field are active simultaneously, a unique property enabling versatile functionalities. When using CrO₂, the demagnetization property of CrO₂ upon heating allows this device to produce an additional thermal induction and optically controllable capability. Additionally, this memory transistor has several outstanding features, including cost effectiveness, fast response time, touchless control, and mechanical flexibility. All these characteristics enable to diversify the applications of our designed nonvolatile memory transistor in several emerging technologies, including communications, touchless devices, and wearable electronics.