The adoption of epidermal electronics into everyday life requires new design and fabrication paradigms, transitioning away from traditional rigid, bulky electronics towards soft devices that adapt ...with high intimacy to the human body. Here, a new strategy is reported for fabricating achieving highly stretchable “island‐bridge” (IB) electrochemical devices based on thick‐film printing process involving merging the deterministic IB architecture with stress‐enduring composite silver (Ag) inks based on eutectic gallium‐indium particles (EGaInPs) as dynamic electrical anchors within the inside the percolated network. The fabrication of free‐standing soft Ag‐EGaInPs‐based serpentine “bridges” enables the printed microstructures to maintain mechanical and electrical properties under an extreme (≈800%) strain. Coupling these highly stretchable “bridges” with rigid multifunctional “island” electrodes allows the realization of electrochemical devices that can sustain high mechanical deformation while displaying an extremely attractive and stable electrochemical performance. The advantages and practical utility of the new printed Ag‐liquid metal‐based island‐bridge designs are discussed and illustrated using a wearable biofuel cell. Such new scalable and tunable fabrication strategy will allow to incorporate a wide range of materials into a single device towards a wide range of applications in wearable electronics.
Liquid metal based materials offer distinct advantages for the fabrication of island‐bridge electrochemical electronics. This study describes a novel approachmerging the unique advantages of deterministic architectures with stress‐enduring nanoengineered inks, supported with dynamic electrical anchors inside the percolated network. Versatile applications with various functional materials are also demonstrated by printing epidermal biofuel cells tested successfully on human subjects.
Ga doping in indium zinc oxide (IZO)‐based amorphous‐oxide semiconductors (AOSs) promotes the formation of oxide‐lattice structures with oxygen vacancies at low annealing temperatures, which is ...essential for acceptable thin‐film‐transistor performance (see figure). The mobility dependence on annealing temperature and AOS composition are analyzed and the chemical role of Ga is clarified, as required for solution‐processed, low‐temperature‐annealed AOSs.
The ability to form arbitrary 3D structures provides the next level of complexity and a greater degree of freedom in the design of electronic devices. Since recent progress in electronics has ...expanded their applicability in various fields in which structural conformability and dynamic configuration are required, high‐resolution 3D printing technologies can offer significant potential for freeform electronics. Here, the recent progress in novel 3D printing methods for freeform electronics is reviewed, with providing a comprehensive study on 3D‐printable functional materials and processes for various device components. The latest advances in 3D‐printed electronics are also reviewed to explain representative device components, including interconnects, batteries, antennas, and sensors. Furthermore, the key challenges and prospects for next‐generation printed electronics are considered, and the future directions are explored based on research that has emerged recently.
Recent remarkable advances in 3D‐printable functional materials and high‐resolution 3D printing methods to fabricate freeform electronics are discussed in this review as their latest applications in various device components, with perspectives on the future direction of 3D printing technologies.
Zinc‐ion hybrid supercapacitors (ZIHCs) are promising electrochemical energy storage system candidates owing to their eco‐friendliness, low‐cost, reliable safety, and high‐power density. Of ...particular note, ZIHCs are desirable alternatives to lithium‐ion batteries (LIBs) because they can overcome the disadvantages of LIBs, such as the explosion hazard and the complex manufacturing process. Nevertheless, the low specific capacity of ZIHCs caused by their limited active sites and poor cycling stability because of their low wettability and irreversible Zn dendrite formation at the electrode has hindered their commercial application. Herein, for the first time, the fabrication and interfacial engineering of ZIHCs using vanadium (IV) oxide sulfate (VOSO4) as an additive chemistry agent is described, and the effect of the additive on the electrochemical performance is demonstrated. After the activation process, the resultant supercapacitor exhibits a zinc vanadium hydrate (ZVO) layer on both the anode and cathode. The electrochemical role of the ZVO layer on the electrodes are as follows: i) improved active sites for Zn‐ion intercalation at the cathode, ii) enhanced wettability between electrolyte and electrodes, and iii) buffer layer for the suppression of undesirable and irreversible Zn dendrites at the anode.
A vanadium (IV) oxide sulfate as an additive chemistry agent in electrolytes for zinc‐ion hybrid supercapacitors is proposed. The zinc vanadium hydrate layer on the zinc anode and carbon cathode is successfully developed using electrochemical activation using additive chemistry. The fabricated supercapacitor exhibits a high energy density of 340.2 W h kg−1 and excellent cycling stability for 10 000 cycles.
Here, we report the facile one‐step fabrication of rationally designed hybrid gate dielectric films for low‐voltage organic thin‐film transistors. To generate facile one‐step fabricated and ...solution‐processed organic–inorganic hybrid dielectric films with high dielectric properties, we designed the multicomponent precursor solution by employing high‐k oxide materials to attain a large capacitance and cross‐linkable agents to allow for processability and reducing the surface energy of dielectric films. After spin‐coating with the precursor solution and the subsequent thermal annealing process, we obtained cross‐linked organic–inorganic hybrid dielectric films, exhibiting excellent dielectric properties with a low leakage current density (~10−5 A/cm2) and high capacitance (295 nF/cm2). The effectiveness of the hybrid dielectrics was demonstrated by realizing high‐performance organic thin‐film transistors at low operating voltages, mobility up to 0.31 cm2/V/s, high on/off current ratio (~105), and low threshold voltage (−0.8 V).
The facile one‐step fabrication of rationally designed hybrid gate dielectric films for low‐voltage organic thin‐film transistors.
Herein, we report the facile fabrication of rationally designed, high‐performance organic–inorganic hybrid dielectric films constructed by combining a one‐step solution processing and ultraviolet ...(UV) irradiation under ambient conditions. For the exceptional dielectric properties and facile fabrication process, we use bifunctional polyhedral oligomeric silsesquioxane (POSS) with UV cross‐linking and hydrophobic properties to prepare precursor solutions for the hybrid dielectric films. The bifunctional POSS enables the fabrication of a dense network of hybrid films with UV curing at under ambient conditions. The prepared hybrid gate dielectrics exhibit high capacitance (~300 nF/cm2), exceptional surface smoothness (root‐mean‐square roughness <0.4 nm), and excellent leakage current properties (10−6 A/cm2 at 2 MV/cm). In addition, the hydrophobic function of bifunctional POSS enables the low surface energy of fabricated hybrid gate dielectrics without further treatment. Pentacene‐based organic thin‐film transistors, fabricated with a hybrid dielectric, function well at low voltage with excellent thin‐film transistor performances.
The ultraviolet (UV) cross‐linked hybrid gate dielectric films using bifunctional polyhedral oligomeric silsesquioxane (POSS) for low‐voltage organic thin‐film transistors.
The rechargeable aqueous Zn ion battery (ZIB) is a promising candidate for next-generation energy storage technology due to its low cost, low flammability, inherent safety, and high theoretical ...capacity. Nevertheless, the β-MnO2 cathode material continues to be limited by inactive ion insertion and transport kinetics due to a relatively narrow tunneling pathway, thus leading to low capacity and rate capabilities. Hence, to achieve a high-performance ZIB, the presence of lattice and defect structures in the β-MnO2 is required to promote the electrochemical reactions. Herein, for the first time, a β-MnO2 cathode with a hierarchical structure consisting of spheres of interlaced nanosheets is introduced via efficient defect engineering using fluorine (F)-doping and oxygen vacancies, thus leading to improved ion insertion and transport kinetics along with an enhanced electrical conductivity. The ZIB is shown to exhibit a high energy density (288 W h kg−1 at a power density of 90 W kg−1), a superior high-rate performance (energy density of 158 W h kg−1 at a power density of 1800 W kg−1), and a capacity retention (85% after up to 150 cycles). These results highlight the potential of defect-engineered cathode materials for the enhanced electrochemical performance of rechargeable aqueous batteries.
Herein, we report on the preparation of new solution‐processed and low‐temperature condensed organic–inorganic hybrid dielectric films and their electrical properties for applications in low‐power ...organic thin‐film transistors (OTFTs). The low‐temperature condensed hybrid dielectric films (~19 nm thick) were simply fabricated by spin coating a mixture solution of a zirconium chloride and synthesized bifunctional phosphonic acid organic reagents, followed by annealing at a relatively low temperature (~90 °C). The prepared hybrid dielectric films exhibited excellent dielectric properties (low leakage current density < 10−6 A/cm2 and high capacitance of 520 nF/cm2) as well as a smooth surface (RMS roughness <0.3 nm). Consequently, the pentacene‐based OTFTs were fabricated using these hybrid dielectrics and functioned effectively at a relatively low operating bias (−2 V) and exhibited great TFT characteristics (hole mobility: 0.3 cm2/V/s, low threshold voltage: −0.7 V, low subthreshold swing: 0.17 V/dec, on/off current ratio: 105).
We report on the preparation of new solution‐processed and low‐temperature condensed organic–inorganic hybrid dielectric films and their electrical properties for applications in low‐power organic thin‐film transistors (OTFTs).
The first example of an n-type 1benzothieno3,2-b1benzothiophene (BTBT)-based semiconductor, D(Ph F CO)-BTBT, has been realized via a two-step transition-metal-free process without using ...chromatographic purification. Physicochemical and optoelectronic characterizations of the new semiconductor were performed in detail, and the crystal structure was accessed. The new molecule exhibits a large optical band gap (∼2.9 eV) and highly stabilized (ΔE LUMO = 1.54 eV)/π-delocalized lowest unoccupied molecular orbital (LUMO) mainly comprising the BTBT π-core and in-plane carbonyl units. The effect of out-of-plane twisted (64°) pentafluorophenyl groups on LUMO stabilization is found to be minimal. Polycrystalline D(Ph F CO)-BTBT thin films prepared by physical vapor deposition exhibited large grains (∼2–5 μm sizes) and “layer-by-layer” stacked edge-on oriented molecules with an in-plane herringbone packing (intermolecular distances ∼3.25–3.46 Å) to favor two-dimensional (2D) source-to-drain (S → D) charge transport. The corresponding TC/BG-OFET devices demonstrated high electron mobilities of up to ∼0.6 cm2/V·s and I on/I off ratios over 107−108. These results demonstrate that the large band gap BTBT π-core is a promising candidate for high-mobility n-type organic semiconductors and, combination of very large intrinsic charge transport capabilities and optical transparency, may open a new perspective for next-generation unconventional (opto)electronics.
Recent advances in semiconductor performance made possible by organic π-electron molecules, carbon-based nanomaterials, and metal oxides have been a central scientific and technological research ...focus over the past decade in the quest for flexible and transparent electronic products. However, advances in semiconductor materials require corresponding advances in compatible gate dielectric materials, which must exhibit excellent electrical properties such as large capacitance, high breakdown strength, low leakage current density, and mechanical flexibility on arbitrary substrates. Historically, conventional silicon dioxide (SiO2) has dominated electronics as the preferred gate dielectric material in complementary metal oxide semiconductor (CMOS) integrated transistor circuitry. However, it does not satisfy many of the performance requirements for the aforementioned semiconductors due to its relatively low dielectric constant and intransigent processability. High-k inorganics such as hafnium dioxide (HfO2) or zirconium dioxide (ZrO2) offer some increases in performance, but scientists have great difficulty depositing these materials as smooth films at temperatures compatible with flexible plastic substrates. While various organic polymers are accessible via chemical synthesis and readily form films from solution, they typically exhibit low capacitances, and the corresponding transistors operate at unacceptably high voltages. More recently, researchers have combined the favorable properties of high-k metal oxides and π-electron organics to form processable, structurally well-defined, and robust self-assembled multilayer nanodielectrics, which enable high-performance transistors with a wide variety of unconventional semiconductors. In this Account, we review recent advances in organic–inorganic hybrid gate dielectrics, fabricated by multilayer self-assembly, and their remarkable synergy with unconventional semiconductors. We first discuss the principals and functional importance of gate dielectric materials in thin-film transistor (TFT) operation. Next, we describe the design, fabrication, properties, and applications of solution-deposited multilayer organic–inorganic hybrid gate dielectrics, using self-assembly techniques, which provide bonding between the organic and inorganic layers. Finally, we discuss approaches for preparing analogous hybrid multilayers by vapor-phase growth and discuss the properties of these materials.
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