Complementary of Ferroelectric and Floating Gate Structure for High Performance Organic Nonvolatile Memory

Organic thin film transistor (OTFT) based nonvolatile memory has made significant progress due to its biocompatibility, flexibility, and low cost, in which ferroelectric transistor memory and floating gate transistor memory play the main roles in organic nonvolatile transistor memory. Here, a novel layered hybrid structure OTFT nonvolatile memory is invented by combining ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) P(VDF-TrFE) with a floating gate layer utilizing CdSe/ZnS quantum dots (QDs), which integrates the advantages of ferroelectric memory and floating gate memory. The core-shell structured CdSe/Zns QDs are acted as robust charge trapping centers due to their band structure similar to a quantum well, preventing the back diffuse of trapped charges, while P(VDF-TrFE) provides additional polarized electric field to modulate the capture of charge. The resultant devices exhibit high on-state current (approximate to 10(-5) A), low off-state current (approximate to 10(-10) A), excellent switch ratio (approximate to 10(5)), and retention characteristic (>10(4) s). Furthermore, a superior memory window, more than 85.6% of scanning voltage range, higher than most reported organic transistor memories, is achieved, which endows the device wide operating condition and significant discrimination between on and off state. The fine-structured OTFT memory opens up a unique path for desirable memory to meet the growing demand of microelectronic industry.