• organic memory;
  • electrets;
  • NAND flash;
  • organic field-effect transistors;
  • printed electronics


High-performance top-gated organic field-effect transistor (OFET) memory devices using electrets and their applications to flexible printed organic NAND flash are reported. The OFETs based on an inkjet-printed p-type polymer semiconductor with efficiently chargeable dielectric poly(2-vinylnaphthalene) (PVN) and high-k blocking gate dielectric poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) shows excellent non-volatile memory characteristics. The superior memory characteristics originate mainly from reversible charge trapping and detrapping in the PVN electret layer efficiently in low-k/high-k bilayered dielectrics. A strategy is devised for the successful development of monolithically inkjet-printed flexible organic NAND flash memory through the proper selection of the polymer electrets (PVN or PS), where PVN/- and PS/P(VDF-TrFE) devices are used as non-volatile memory cells and ground- and bit-line select transistors, respectively. Electrical simulations reveal that the flexible printed organic NAND flash can be possible to program, read, and erase all memory cells in the memory array repeatedly without affecting the non-selected memory cells.