Patterning Vertically Grown Gold Nanowire Electrodes for Intrinsically Stretchable Organic Transistors

Abstract

facile fabrication. [15][16][17][18] Metal nanowires (gold, silver, copper, etc.) [19][20][21][22][23][24] and carbon based materials such as carbon nanotubes (CNTs) and graphene, [25][26][27][28][29][30][31] have received tremendous research attention in constructing intrinsically stretchable electrodes for organic electronics.Among those choices, raw materials cost of gold may not be the lowest, but it offers superior advantages in biomedical applications of wearable and implantable electronics, due to the attributes including high conductivity, mechanical robustness, chemical inertness, and biocompatibility. [32][33][34] For example, the conductivity of gold is two orders higher than carbon based materials. [35] Also, gold has been known to be anti-oxidative and anti-corrosive, while silver or copper fails in maintaining a long-term stability in complex body fluidic environments. Furthermore, the work function of gold is close to the HOMO levels of many p-type organic semiconductors such as poly(3-hexylthiophene) (P3HT) and pentacene, offering small hole-injection barriers and low contact resistance at metal-organic semiconductor interfaces. [36][37][38][39][40] Although little research attention had been paid to improving contact resistance in stretchable organic transistors because the state-of-the-art device performance is mostly hindered by channel resistance, advances in high mobility organic semiconductors will make contact resistance increasingly crucial in determining device performance, rendering gold materials more favorable in stretchable organic electronics. [41][42][43][44][45][46] Nevertheless, gold nanomaterials based electrodes have hitherto yet been well developed for intrinsically stretchable transistors. 2D gold nanosheets have been assembled to stretchable electrodes for P3HT fiber based stretchable organic transistors with good mechanical and electrical performance. [47][48][49] However, 2D gold nanosheets, fabricated at relatively high temperature (95 °C), are rigid in nature and the fabrication process is incompatible to the patterning processes via conventional photo lithography, and hence may limit device density, mechanical robustness, and scalability. [15] 1D gold nanowires (AuNWs) have emerged as an excellent materials candidate for serving as electrodes in stretchable electronics because of their mechanical flexibility, ease of fabrication, and Advances in large-area organic electronics for sensor arrays and electronic skins demand highly stretchable, patternable, and conformal electrodes to minimize contact resistance when sensing devices are mechanically deformed. Gold is an excellent electrode material with work function matching well with p-type organic transistors. However, it is non-trivial to fabricate highly stretchable gold electrodes for stretchable organic electronics. Here, by combining the advantages of both top-down patterning and bottomup synthesis, a new materials platform of patterned vertically grown gold nanowires (AuNWs) for constructing intrinsically stretcha...

Local Crack‐Programmed Gold Nanowire Electronic Skin Tattoos for In‐Plane Multisensor Integration

“…Due to their unique accordion fan‐like deformation in conjunction with robust interfacial bonding chemistry, such standing gold nanowires can serve as highly durable and stretchable materials platforms for various sensing applications. Using poly(methyl methacrylate) as the sacrificial layer, we can embed standing gold nanowires into polydimethylsiloxane (PDMS), obtaining elastic strain‐insensitive gold conductors (Figure S1, Supporting Information). The embedment is confirmed by cross‐sectional scanning electron microscope (SEM) image (Figure S2, Supporting Information).…”

Intrinsically Stretchable Fuel Cell Based on Enokitake‐Like Standing Gold Nanowires

“…As shown in Figure 4A,C, CV curves of these two stretchable electrodes under these three deformed states were measured in 0.1 m NaOH solution containing 0.1 m C 2 H 5 OH. [32,34,44] This trend was much more pronounced for tail-side exposed electrodes which exhibited an obvious reduction in peak currents ( Figure 4E). In addition, the effect of strain upon the performance of the two electrodes was also investigated, as shown in Figure 4B,D.…”

“…From 10% to 50% strain, the CV peaks of both electrodes were decreasing, which can be attributed to the decreased conductivity and increased resistances. [32,34,44] This trend was much more pronounced for tail-side exposed electrodes which exhibited an obvious reduction in peak currents ( Figure 4E). The results of some key parameters for the two electrodes are compared under different strains and are presented in Table S2 in the Supporting Information.…”

Flexible electronics based on one‐dimensional and two‐dimensional hybrid nanomaterials

“…Accordingly, many studies have been conducted that applied AuNWs to flexible electronics. Zhu et al fabricated stretchable electrodes by embedding AuNWs that were grown vertically from patterned gold seeds in PDMS and developed an intrinsically stretchable organic transistor array using poly(3‐hexylthiophene) (P3HT) (Figure A,B). Transistors that use a gel electrolyte as dielectric showed excellent mechanical durability without significant performance degradation, even when a 100% strain was applied (Figure C).…”

“…F, Calibration plot of the chronoamperometric responses of the stretchable fiber‐based glucose sensor from 0% to 200% strain. A‐C, Reproduced with permission . Copyright 2018, Wiley‐VCH.…”