Flexible Memristors Fabricated through Sol-Gel Hydrolysis

Abstract

Memristors were fabricated on flexible polyethylene terephthalate substrates consisting of an oxide film generated through hydrolysis of a spun-on sol-gel. X-ray photoelectron spectroscopy, spectroscopic ellipsometry, transmission electron microscopy, and electron energy loss spectroscopy measurements indicated that the oxide films were amorphous TiO2 with a significant fraction of organic material, causing a heterogeneous surface morphology. Despite the morphology and the organic material, these memristors exhibit switching similar to "traditional" memristors. Also, current-voltage (I-V) measurements suggest that this switching was not due to the electric field in the memristors. Additionally, thermal imaging measurements and I-V measurements performed after sectioning the memristors suggest that conduction occurred via localized conduction pathways. Capacitance-frequency and conductance-frequency measurements indicate an additional dielectric loss mechanism was present prior to switching to the higher current state. This loss mechanism is attributed to dipoles present in the organic components of the oxide films from the original sol-gel.

Benchtop Fabrication of Memristive Atomic Switch Networks

“…In contrast to complex lithographic methods, solution-phase approaches have been shown to produce functional memristive devices using spin-coated solgel films alongside anodic electrochemical deposition [22][23][24][25][26][27][28][29]. Electrochemistry in particular offers a divergent approach for the fabrication of metallic structures.…”

Switching mechanisms in flexible solution-processed TiO2memristors

“…Figures 6(c) and (d) show evidence of multiple hot spots, which would be indicative of multiple parallel conduction paths. Previous reports on IR measurements of TiO 2 memristors [27] and scanning transmission x-ray microscopy measurements of TiO 2 memristors [24] have shown evidence of only one conduction path per device. Furthermore, other measurements in this study indicated that while some memristors exhibited multiple hot spots, others exhibited only one hot spot.…”

“…The difference in switching bias between the 47 nm thick 100 µm devices and thinner devices (figure 2(a)) raises the question of whether the mechanism is field-or charge-mediated [1,19]. If the switching behavior were field-dependent, one would expect a linear correlation between the device thickness and the switching bias [27]. This expected linear correlation is plotted in figure 2(a) by using the switching bias and thickness of the thinnest sample and extrapolating the resulting expected trend in switching bias for the thicker samples.…”

Unconventional Inorganic‐Based Memristive Devices for Advanced Intelligent Systems

“…A variety of researchers have studied direct fabrication methods of flexible memories on a plastic substrate utilizing low temperature processes such as vacuum deposition, wet processing, and printing methods . Jang et al fabricated a Ag/Ag 2 Se/Au RS memory on a flexible poly‐ethylene‐naphthalate (PEN) substrate using a wet method, as shown in Figure a,b.…”