Controllable Shifts in Threshold Voltage of Top-Gate Polymer Field-Effect Transistors for Applications in Organic Nano Floating Gate Memory

Abstract

Organic field-effect transistor (FET) memory is an emerging technology with the potential to realize light-weight, low-cost, flexible charge storage media. Here, solution-processed poly[9,9-dioctylfluorenyl-2,7-diyl]-co-(bithiophene)] (F8T2) nano floating gate memory (NFGM) with a top-gate/bottom-contact device configuration is reported. A reversible shift in the threshold voltage (V(Th)) and reliable memory characterics was achieved by the incorporation of thin Au nanoparticles (NPs) as charge storage sites for negative charges (electrons) at the interface between polystyrene and cross-linked poly(4-vinylphenol). The F8T2 NFGM showed relatively high field-effect mobility (mu(FET)) (0.02 cm(2) V(-1) s(-1)) for an amorphous semiconducting polymer with a large memory window (ca. 30 V), a high on/off ratio (more than 10(4)) during writing and erasing with an operation voltage of 80V of gate bias in a relatively short timescale (less than 1 s), and a retention time of a few hours. This top-gated polymer NFGM could be used as organic transistor memory element for organic flash memory.