Conjugated Polymers Containing EDOT Units as Novel Materials for Electrochromic and Resistance Memory Devices

Four new multifunctional polymers (P1, P2, P3, and P4) containing EDOT units were synthesized by the Stille coupling reaction. A PL spectrum test found that the introduction of large conjugated groups led to strong fluorescence emission in all polymers. Among the electrochromic and switch properties, these polymer films exhibited reversible color changes, as well as good coloring efficiency. Electrochemical experiments found that the initial oxidation potentials of the polymers were 1.27 V, 1.67 V, 1.78 V, and 1.58 V, respectively. Among them, P3 showed a higher coloring efficiency (283.3 cm²·C^-1), and P2 showed a shorter response time (t_c = 2.2 s, t_b = 2.8 s). These polymers all exhibited electrochromic and resistive switching storage characteristics. They have good solubility in many organic solvents. In the resistance switch memory characteristics, all polymers had obvious memristive properties, and P4 exhibited a larger switch current ratio (2527.42) and a smaller threshold voltage (0.9 V).

Bistable non-volatile resistive memory devices based on ZnO nanoparticles embedded in polyvinylpyrrolidone

The resistive random access memory (RRAM) devices based on polyvinylpyrrolidone (PVP) and PVP:PVP:zinc oxide nanoparticle (ZnO NP) active layers have bistable electrical switching behavior. Herein, via a series of storage performance tests, it was proved that the ITO/PVP:ZnO/Al device has a higher ON/OFF current ratio and better memory performance than the ITO/PVP/Al device. Moreover, at 13 wt% concentration of ZnO NPs, optimal storage performance was obtained, the switch state current ratio significantly increased, and the threshold voltage obviously decreased. The conduction mechanism of the devices was further discussed. The device having inorganic nanoparticles embedded in the polymer has excellent storage performance, which has potential application value in data storage.

The resistive random access memory (RRAM) devices based on polyvinylpyrrolidone (PVP) and PVP:PVP:zinc oxide nanoparticle (ZnO NP) active layers have bistable electrical switching behavior.

Novel carbazole-based donor-isoindolo[2,1-a]benzimidazol-11-one acceptor polymers for ternary flash memory and light-emission

Three novel donor-acceptor polymers (PCz0, PCz2 and PCz4) based on 9-(9-heptadecanyl)-9H-carbazole and isoindolo[2,1-a]benzimidazol-11-one with fluorine substituents (0, 2 and 4) on the acceptor unit were prepared by Suzuki polymerization. The synthesized polymers were studied by theoretical calculation, and optical and electrochemical characterizations to further investigate the performance of memory storage and light-emission. The memory devices of the three polymers all exhibited obvious ternary flash behavior with total ON/OFF state current ratio around 104 and threshold voltages below 3.0 V, with no other blending or doping. Bright emissions of an electroluminescence device based on PCz0 was obtained at 556 nm, the maximum brightness was 2006 cd m-2 with EQE of 0.21%. The results suggested that polymers with the structure of carbazole-based donor as backbone and isoindolo[2,1-a]benzimidazol-11-one segment as acceptor could be excellent materials for memory storage and light-emitting applications with further investigation and could be used for further design of other new polymer systems.