Poly-4-vinylphenol and poly(melamine-co-formaldehyde)-based graphene passivation method for flexible, wearable and transparent electronics

Abstract

Next generation graphene-based electronics essentially need a dielectric layer with several requirements such as high flexibility, high transparency, and low process temperature. Here, we propose and investigate a flexible and transparent poly-4-vinylphenol and poly(melamine-co-formaldehyde) (PVP/PMF) insulating layer to achieve intrinsic graphene and an excellent gate dielectric layer at sub 200 °C. Chemical and electrical effects of PVP/PMF layer on graphene as well as its dielectric property are systematically investigated through various measurements by adjusting the ratio of PVP to PMF and annealing temperature. The optimized PVP/PMF insulating layer not only removes the native -OH functional groups which work as electron-withdrawing agents on graphene (Dirac point close to zero) but also shows an excellent dielectric property (low hysteresis voltage). Finally, a flexible, wearable, and transparent (95.8%) graphene transistor with Dirac point close to zero is demonstrated on polyethylene terephthalate (PET) substrate by exploiting PVP/PMF layer which can be scaled down to 20 nm.

Poly-4-vinylphenol (PVP) and Poly(melamine-co-formaldehyde) (PMF)-Based Atomic Switching Device and Its Application to Logic Gate Circuits with Low Operating Voltage

“…In addition, the variation of the off current narrowed as the ratio of PMF to PVP increased, from between 10 –6 and 6 × 10 –4 A in the 50% device to between 10 –8 and 10 –7 A in the 100% device. This is because the electrical insulating property of the PVP/PMF electrolyte was improved through the cross-linking mechanism brought about by increasing the PVP/PMF ratio . Although a very low off current, approximately 10 –11 A was achieved in the 150% sample, the on/off-current ratio and distribution of the off current could not be confirmed because that device did not operate as an atomic switch.…”

“…We also expected the composite ratio of PMF to PVP to affect the on/off-current ratio because the electrical insulating property of the PVP/PMF electrolyte normally improves by optimizing the ratio of PMF to PVP Figure d shows the on/off currents extracted from the accumulated I – V curves ( V read = 0.2 V), where the off-current level decreased from 6 × 10 –5 (50% device) to 6 × 10 –8 A (100% device) and the on/off-current ratio was subsequently increased by 100 times (10 and 10 3 for 50 and 100% devices, respectively).…”

Ultra‐Flexible, “Invisible” Thin‐Film Transistors Enabled by Amorphous Metal Oxide/Polymer Channel Layer Blends

“…In this contribution, we report the first demonstration of solution‐processed amorphous In 2 O 3 films achieved by doping with an insulating polymer [poly(4‐vinylphenol) (PVP)], affording high‐performance, transparent, and ultra‐flexible TFTs at processing temperatures as low as 225 °C. PVP was selected due to the excellent solubility of this polymer in the In 2 O 3 precursor formulation solution as well as the presence of hydroxyl groups which should favor coordination to the MO lattice.…”

Fabrication of graphene-nanoflake/poly(4-vinylphenol) polymer nanocomposite thin film by electrohydrodynamic atomization and its application as flexible resistive switching device

“…Many high dielectric constant polymers have been studied for memristive behaviour. Poly(4-vinlyphenol) (PVP) finds application as dielectric in thin-film transistors (TFTs) [18,19], resistive switching and writeonce read-many (WORM) memories [20]. Several polymer/nanoparticle [21,22] memory devices have been reported.…”