Solution-Processed Dual Gate Ferroelectric-Ferroelectric Organic Polymer Field-Effect Transistor For The Multibit Nonvolatile Memory

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,I-OUTs) results from the independent programming voltages of the dual gates. An excellent distinct six-level I-M,I-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.