5 research outputs found
Laser Sweeping Lithography: Parallel Bottom-up Growth Sintering of a Nanoseed–Organometallic Hybrid Suspension for Ecofriendly Mass Production of Electronics
We present a novel
laser sweeping lithography (LSL) process, revolving
around an ecofriendly mass production method, to fabricate conductive
patterns in parallel with no restriction on the type of substrate.
Particle-free organometallic solution is reformulated in-process into
a nanoseed−organometallic hybrid suspension, via an incomplete
thermal decomposition using radiative heating. The growth sintering
undergoing a series of ion precipitation, clustering, growing, and
agglomeration procedures is then initiated by irradiating a line-modulated
diode laser of a near-infrared wavelength through a thermally enforced
laser mask on the hybrid suspension. This leads to the concurrent
parallel production of silver conductors with a high-conductivity
(2.9 μΩ·cm), durability, and resolution of 5 μm
on the corresponding to mask openings, without the need of any additional
steps and corrosive chemicals. This method is highly effective for
large-area fabrication of high-density electronics, as the production
time proportionally decreases with increased pattern density and area,
compared to conventional laser fabrication methods based on a single
laser spot. Therefore, the LSL process is suitable for ecofriendly
mass production of various electronic devices in industrial environments
Self-Generated Nanoporous Silver Framework for High-Performance Iron Oxide Pseudocapacitor Anodes
The rapid development
of electric vehicles is increasing the demand for next-generation
fast-charging energy storage devices with a high capacity and long-term
stability. Metal oxide/hydroxide pseudocapacitors are the most promising
technology because they show a theoretical capacitance that is 10–100
times higher than that of conventional supercapacitors and rate capability
and long-term stability that are much higher than those of Li-ion
batteries. However, the poor electrical conductivity of metal oxides/hydroxides
is a serious obstacle for achieving the theoretical pseudocapacitor
performance. Here, a nanoporous silver (np-Ag) structure with a tunable
pore size and ligament is developed using a new silver halide electroreduction
process. The structural characteristics of np-Ag (e.g., large specific
surface area, electric conductivity, and porosity) are desirable for
metal oxide-based pseudocapacitors. This work demonstrates an ultra-high-capacity,
fast-charging, and long-term cycling pseudocapacitor anode via the
development of an np-Ag framework and deposition of a thin layer of
Fe<sub>2</sub>O<sub>3</sub> on its surface (np-Ag@Fe<sub>2</sub>O<sub>3</sub>). The np-Ag@Fe<sub>2</sub>O<sub>3</sub> anode shows a capacitance
of ∼608 F g<sup>–1</sup> at 10 A g<sup>–1</sup>, and ∼84.9% of the capacitance is retained after 6000 charge–discharge
cycles. This stable and high-capacity anode, which can be charged
within a few tens of seconds, is a promising candidate for next-generation
energy storage devices
Simultaneously Enhancing the Cohesion and Electrical Conductivity of PEDOT:PSS Conductive Polymer Films using DMSO Additives
Conductive
polymer polyÂ(3,4-ethyleneÂdioxyÂthiophene):ÂpolyÂ(styreneÂsulfonate)
(PEDOT:PSS) has attracted significant attention as a hole transport
and electrode layer that substitutes metal electrodes in flexible
organic devices. However, its weak cohesion critically limits the
reliable integration of PEDOT:PSS in flexible electronics, which highlights
the importance of further investigation of the cohesion of PEDOT:PSS.
Furthermore, the electrical conductivity of PEDOT:PSS is insufficient
for high current-carrying devices such as organic photovoltaics (OPVs)
and organic light emitting diodes (OLEDs). In this study, we improve
the cohesion and electrical conductivity through adding dimethyl sulfoxide
(DMSO), and we demonstrate the significant changes in the properties
that are dependent on the wt % of DMSO. In particular, with the addition
of 3 wt % DMSO, the maximum enhancements for cohesion and electrical
conductivity are observed where the values increase by 470% and 6050%,
respectively, due to the inter-PEDOT bridging mechanism. Furthermore,
when OLED devices using the PEDOT:PSS films are fabricated using the
3 wt % DMSO, the display exhibits 18% increased current efficiency
Highly Controlled Nanoporous Ag Electrode by Vaporization Control of 2‑Ethoxyethanol for a Flexible Supercapacitor Application
Controlling the surface
morphology of the electrode on the nanoscale
has been studied extensively because the surface morphology of a material
directly leads to the functionalization in various fields of studies.
In this study, we designed a simple and cost-effective method to fine-tune the surface morphology
and create controlled nanopores on the silver electrode by utilizing
2-ethoxyethanol and two successive heat treatments. High electrical
conductivity and mechanical robustness of nanoporous silver corroborate
its prospect to be employed in various applications requiring a certain
degree of flexibility. As a proof-of-concept, a high-performance supercapacitor
was fabricated by electrodepositing MnO<sub>2</sub>. This method is
expected to be useful in various electronic applications as well as
energy storage devices
Transversally Extended Laser Plasmonic Welding for Oxidation-Free Copper Fabrication toward High-Fidelity Optoelectronics
Laser direct processing is a promising
approach for future flexible
electronics because it enables easy, rapid, scalable, and low-temperature
fabrication without using expensive equipment and toxic material.
However, its application for nanomaterials with high chemical susceptibility,
such as representatively Cu, is limited because severe oxidation occurs
under ambient conditions. Here, we report the methodology of a transversally
extended laser plasmonic welding
process, which outstandingly improves the electrical performance of
a Cu conductor (4.6 μΩ·cm) by involving the spatially
concurrent laser absorption to the surface oxide-free Cu nanoparticles
(NPs). Physical/chemical properties of fabricated Cu conductors are
fully analyzed in perspectives of the mechanism based on the thermo-physical-chemical
interactions between photon energy and pure Cu NPs. The resultant
Cu conductors showed an excellent durability in terms of bending and
adhesion. Furthermore, we successfully demonstrated a single layer
Cu-mesh-based touch screen panel (TSP) on thermally sensitive polymer
film as a breakthrough of typical metal oxide-based transparent touch
sensors. The Cu metal mesh exhibited high transmittance (95%) and
low sheet resistance (30 Ω/square). This self-capacitance type
and multitouchable TSP operated with a fast response, high sensitivity,
and durability