Filament theory based WORM memory devices using aluminum/poly(9-vinylcarbazole)/aluminum structures

Abstract

Spin coated poly(N-vinylcarbazole) (PVK) sandwiched between thermally evaporated aluminum (Al) electrodes on a glass substrate showed unipolar Write Once Read Many times (WORM) characteristics. The pristine devices were in the low resistance ON state exhibiting ohmic behavior and at a voltage near -2 V, they switched abruptly to the high resistance OFF state showing space charge limited current (SCLC). We suggest that the rupturing of metallic filaments due to Joule heating may explain the effect. The WORM devices exhibited an ON/OFF ratio of 10(8), a retention of 1000 s and an endurance of ∼10(6) cycles in both ON and OFF states.

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

“…The devices were kept in the OFF state for all subsequent sweeps, thus enabling them to be used as write-once-read-many times (WORM) devices. 20 It is noteworthy that when the top electrode was initially biased ''+'' relative to the bottom, the device also showed up WORM memory effect. As shown in Fig.…”

“…The resistivity of film is increased with the decreasing of SWCNT content in PEDOT: PSS matrix, as shown in Fig. 20 What is noteworthy is that, when the top electrode was initially biased "+" relative to the bottom, the device also showed up WORM memory effect. From the resistivity of PEDOT: PSS+SWCNTs film, we can see that the composite materials are semiconductors (The resistivity of semiconductor is between 10 -6 and 10 8 ⋅ Ω m).…”

Preparing non-volatile resistive switching memories by tuning the content of Au@air@TiO2-h yolk–shell microspheres in a poly(3-hexylthiophene) layer

“…When applying a high DC bias voltage, a large electronic current density is passed through the polymer layer, and the conductive filaments in the PMMA-based active layer may melt, causing a sharp decline in the current. 34 According to the energy diagram for the Al/[Au@air@TiO 2 -h + P3HT]/ITO device (Scheme 2), the energy gap of P3HT is approximately 2.1 eV; 35 the conduction band and valence band of TiO 2 are lower in energy than that of P3HT, indicating that charges obtained from the electrode can easily be transferred from P3HT to the Au@air@TiO 2 -h microspheres. 36 This suggests that the P3HT molecules would capture more electrons when a high DC bias voltage is applied, resulting in higher device conductivity and a more stable current curve during the test.…”

Bistable electrical switching and nonvolatile memory effects by doping different amounts of GO in poly(9,9-dioctylfluorene-2,7-diyl)

“… 7–9 For the last few years, researchers have paid more attention to memristors and have focused on the doping of organic/carbon-based composites. 10,11 Some ORRAM devices have been studied using different organic materials, such as poly( N -vinylcarbazole) (PVK), 12 poly(vinyl phenol), 13 poly(methyl methacrylate) (PMMA), 14 polyimide (PI), 15 triphenylamine (TPA), 16 and so on. CNTs have been doped in organic materials, including poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), poly(3-hexyl-thiophene) (P3HT), 17 PEDOT:PSS, 18 and poly(vinyl alcohol) (PVA).…”