High Electrical Anisotropic Multilayered Self‐Assembled Organic Films Based on Graphene Oxide and PEDOT:PSS

Abstract

Multilayered self‐assembled structures having different constituents are very appealing for preparing novel materials with unusual electrical phenomena not observed on the individual sheets. Here, the fabrication and characterization of aligned multilayered architectures comprised of reduced graphene oxide (rGO) and poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), embedded into polymer electrolytes, are reported. The in‐plane conductivity is five orders of magnitude higher than the cross‐plane value, resulting in the highest anisotropic ratio reported to date for multilayer materials. Temperature‐dependent measurements corroborate the high anisotropic electrical behavior, with charge transport weakly thermally activated (Ea = 33 meV) along the aligned conductive phases. Cross‐plane charge transport fits well with the variable ranging hopping model, presenting an activation energy of 1.0 eV. Such a high anisotropic electrical behavior is explored in a novel transistor architecture where the anisotropic film operates simultaneously as a dielectric layer and as a transistor channel, with the cross‐plane electric field modulating the in‐plane conduction. The device shows ambipolar charge transport; however, the n‐type carrier transport dominates the conduction with the field‐effect mobility of 4.0 cm2 V–1 s–1. A simple and efficient way is presented to use electrical anisotropy to tailor transistors without a lattice mismatch at the dielectric/semiconductor interface.

Photolithographic High‐Conductivity Transparent Conformal rGO/PEDOT:PSS Electrodes for Flexible Skin‐Like All Solution‐Processed Organic Transistors

“…The anisotropic film operates simultaneously as a dielectric layer and as an ambipolar transistor channel, paving the way for fabricating dual-channel inverters. [45] In our work, the introduction of PEDOT:PSS can greatly improve the conductivity of the hybrid electrodes because of the higher conductivity of PEDOT:PSS (typically over 1000 S cm −1 ) than that of rGO (typically at 3.33-71 S cm −1 ). [17,46,47] The low conductivity of rGO originates from the loss of carbon during reduction, residual oxygenated sites, and the physical grain boundaries between the original GO sheets.…”

Multi-channel AgNWs-doped interdigitated organic electrochemical transistors enable sputum-based device towards noninvasive and portable diagnosis of lung cancer

“…Typical output characteristics of SiOECTs with functionalized gate electrode operating in depletion mode was shown in Fig. S7 [ 28 , 29 ]. The drain-source current (I DS ) decreased with increasing bias gate voltage (V G ) [ 30 , 31 ].…”

Field-effect transistors engineered via solution-based layer-by-layer nanoarchitectonics

“…LbL assembly presents a promising approach for creating composite graphitic materials with electrical anisotropy, achieved through simple and affordable experimental protocols. A recent study by Gomes et al [81] reported the fabrication of a self-assembled multilayer composite based on graphene, exhibiting remarkably high electrical anisotropy, with in-plane conductivity measuring five orders of magnitude higher than cross-plane conductivity. This unique property of LbL-assembled materials opens up possibilities for utilizing them as semi-insulators for cross-plane conduction and semiconductors for in-plane conduction.…”