Programmable Digital Memory Characteristics of Nanoscale Thin Films of a Fully Conjugated Polymer

Abstract

This paper reports for the first time the programmable digital memory characteristics of the nanoscale thin films of a fully π-conjugated polymer, poly(diethyl dipropargylmalonate) (pDEDPM) in the absence of doping. This π-conjugated polymer was found to exhibit good solubility in organic solvents and to be easily processed to form nanoscale thin films through the use of conventional solution spin-, roll-, or dip-coating and subsequent drying. Films of the π-conjugated polymer with top and bottom metal electrodes exhibit excellent dynamic random access memory (DRAM) characteristics or write-once-read-many-times (WORM) memory behavior without polarity, depending on the film thickness. All the PI films are initially present in the OFF-state. Films with a thickness of 30 nm were found to exhibit very stable WORM memory characteristics without polarity and an ON/OFF current ratio of 10 6 , whereas films with a thickness of 62-120 nm were found to exhibit excellent DRAM characteristics without polarity and an ON/OFF current ratio as high as 10 8 . These memory characteristics are governed by trap-limited space-charge limited conduction and heterogeneously local filament formation. In these polymer films, both the ester units and the conjugated double bonds of the polymer backbone can act as charge trapping sites. The excellent bistable switching properties and processibility of this π-conjugated polymer mean that it is a promising material for the low-cost mass production of high density and very stable digital nonvolatile WORM memory and volatile DRAM devices.

Bistable electrical switching and nonvolatile memory effect in carbon nanotube–poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) composite films

“…The ON and OFF states of device are stable for up to 1.2×10 4 continuous read pulses of -4 V. The device based on sample C also shows the bi-directionally switchable characteristics. 22 In addition, compared with that of high conductivity states, the slope is larger for low conductivity state; meanwhile the range with the slope larger than 1 is much wider for low conductivity state. 10(a)) with a lower ON/OFF state current 9 ratio of about 2×10 2 at -4 V and exhibits similar WORM memory switching behavior.…”

Solution-processable triarylamine-based high-performance polymers for resistive switching memory devices

“…In addition, memory properties can be tuned by changing the following properties: the electron donor or acceptor in functional donor-acceptor type polymers, linkage, conformation and film thickness of the active polymer layer within the devices. 48,[83][84][85] Donor effect Shen and colleagues synthesized polymers P32/P33 (Scheme 10) consisting of alternating electron-donating carbazole/TPA moieties and electron-accepting phthalimide moieties. 45 These polymers are thermally stable with 5% weight loss over 500°C and T g above 290°C.…”

Structure, electrochemical properties and capacitance performance of polypyrrole electrodeposited onto 1-D crystals of iridium complex

“…Electrochemical impedance parameters determined for 1.5 mm diameter Au disk electrode coated with 1-D-IrCl 2 (CO) 2 electrochemical oxidation of (AsPh 4 )[IrCl 2 (CO) 2 ]. Next, polypyrrole films were synthesized on the iridium needles by oxidative electropolymerization.…”