Solution‐Processed Dual Gate Ferroelectric–Ferroelectric Organic Polymer Field‐Effect Transistor for the Multibit Nonvolatile Memory

Abstract The stable multibit storage operation of solution‐processed organic nonvolatile memories (ONVMs) based on ferroelectric field‐effect transistors (FeFETs) for high density data storage devices are demonstrated. The proposed multibit ONVM structure consists of a p‐type polymer semiconductor sandwiched between poly(vinylidene fluoride‐trifluoroethylene) [P(VDF‐TrFE)] layers serving as ferroelectric gate insulators to form a dual gate ferroelectric–ferroelectric memory transistor (DG Fe‐FeMT). With the extra memory space created by the spatially separated ferroelectrics, a 2‐bit memory representation (“11”, “10”, “01” and “00”) with clear memory margins is achieved due to the bistability of each P(VDF‐TrFE) and the high performance of the polymer semiconductor. The distinct four‐level reading of memory output currents ( I M,OUTs ) results from the independent programming voltages of the dual gates. An excellent distinct six‐level I M,OUTs are also achieved in DG Fe‐FeMT using the intermediate programming voltages. Finally, the possibility of 3−bit, or 8 memory states, are demonstrated by optimizing the bistability and intermediate polarization states of the ferroelectrics without increasing the device area horizontally. The DG Fe‐FeMT has a great potential for cost−effective flexible nonvolatile multibit data storage devices due to its solution‐process and low annealing temperatures.