Highly Conductive Inkjet-Printed PEDOT:PSS Film under Cyclic Stretching

Abstract

Inkjet-printed conductive polymer PEDOT:PSS films have provided a new developing direction for realizing the stretchable transparent electrodes in optoelectronic devices. However, their conductivity and stretchability are limited as the presence of insulating PSS chains, rigid PEDOT conjugated backbone, and stronger inter-chain interactions in the pristine polymer, respectively. Here, we report a PEDOT:PSS film with preferable electrical and mechanical performances by inkjetprinting the formulated printable ink containing PEDOT:PSS, formamide (FA), D-sorbitol (SOR), sodium dodecyl benzene sulfonate (DBSS), and ethylene glycol (EG). The inkjet-printed uniform PEDOT:PSS film exhibits a high conductivity of 1050 S/ cm and sheet resistance of less than 145 Ω/sq on both rigid and flexible substrates. Moreover, the resistance can remain stable after 200 cycles of stretching at 55% strain. The film also presents good stability during repetitive stretching−releasing cycles. The significantly enhanced conductivity of the film lies on the conformational transition of the backbone by secondary doping and post-treatment with FA as well as removing the excess PSS components after phase separation between PEDOT and PSS. Meanwhile, SOR serves as a plasticizer to break the original hydrogen bonds between PSSH chains and provides larger free volume for polymer chain extension, which gives the PEDOT:PSS film the ability to tolerant cyclic tension. This is one of the optimal performances currently reported for inkjet-printed stretchable PEDOT:PSS films. The inkjet-printed PEDOT:PSS film with high conductivity, stretching properties, as well as good biocompatibility exhibits promising prospects as anodes on optoelectronic devices.

Agar-Based Solid Polymer Electrolyte-Containing Ionic Liquid for Sustainable Electrochromic Devices

“…However, the cathodic coloration process does not seem to correspond to any of the reducing currents in the voltammograms. This behavior is attributed to the presence of dissolved oxygen, which 4e- reduction wave overlaps with, and masks, the reduction wave of PEDOT:PSS …”

The role of substrates and electrodes in inkjet-printed PEDOT:PSS thermoelectric generators

“…These substrates were selected as they are the most commonly used in the literature and allow easy comparison with previous reports. 22,27,[35][36][37] In general, the surface energy of the substrate has a strong impact on film morphology. In our experiments, the substrates underwent UVozone treatment in order to increase surface hydrophilicity which is generally required to inkjet-print films with a certain degree of uniformity.…”

“…The variation tendency of conductivity could be due to the change of charge carrier density (according to the well-known equation s = nqm, where n is the charge carrier density, m is the charge carrier mobility, and q is the elementary charge), which may be ascribed to the density change in thin films. 22 Thin film density was also estimated as a function of the number of printed layers as shown in Fig. 3(b), by considering homogeneous films with a constant thickness.…”

“…In particular, inks based on poly (3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) have witnessed remarkable development since the last decade. [20][21][22][23] In aqueous dispersions, PEDOT:PSS tends to form colloidal microparticles with a core-shell structure in which an excess of PSS-rich shell encapsulates the PEDOT-rich core. A PEDOT:PSS mass ratio of 1 : 2.5 or 1 : 6 is typically used for high-conductivity samples.…”

Omnidirectional Printing of PEDOT:PSS for High-Conductivity Spanning Structures

“…In the realm of materials endowed with distinctive conjugated configurations, intrinsically conducting polymers find their applications spanning from bioelectronics, energy storage and conversion, flexible electronics, and antistatic coating to tissue engineering . Among these, poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS) is the most widely used due to its facile processability, favorable electrical conductivity, remarkable stability and inherent biocompatibility. , Conventionally, the concentrated PEDOT:PSS is processed to one-dimensional (1D) isolated fibers via coagulation, garnering extensive utility such as bioelectronics , and microsupercapacitors. , Besides, two-dimensional (2D) patterns of PEDOT:PSS can be achieved by coating, − inkjet printing, , screen printing, , laser patterning, electrogelation, and lithography . The construction method of three-dimensional (3D) PEDOT:PSS structures, despite its broad potential applications in flexible electronics and wearable technologies, etc., remains a bottleneck constraining its development.…”