Electronic Structure and Volume Effect on Thermoelectric Transport in P -Type Bi and Sb Tellurides

Thermoelectric transport properties (Seebeck coefficient, S, and electrical conductivity, σ) of p -type Bi and Sb tellurides are investigated using a first-principles all-electron density-functional approach. We demonstrate that the carrier concentration, band gap, and lattice constants have an important influence on the temperature behavior of S and that the volume expansion by 5.5% in Sb2Te3 results in an increase in S by 33μV/K at 300 K. We argue that in addition to the electronic structure characteristics, the volume also affects the value of S and hence should be considered as an origin of the experimental observations that S can be enhanced by doping Sb2Te3 with Bi (which has a larger ionic size) in Sb sites or by the deposition of thick Bi2Te3 layers alternating with thinner Sb2Te3 layers in a superlattice, Bi2Te3/ Sb2Te3. We show that the optimal carrier concentration for the best power factor of Bi2Te3 and Sb2 Te3 is approximately 1019 cm-

Honeycomb oxide heterostructure: a new platform for Kitaev quantum spin liquid

Kitaev quantum spin liquid, massively quantum entangled states, is so scarce in nature that searching for new candidate systems remains a great challenge. Honeycomb heterostructure could be a promising route to realize and utilize such an exotic quantum phase by providing additional controllability of Hamiltonian and device compatibility, respectively. Here, we provide epitaxial honeycomb oxide thin film Na3Co2SbO6, a candidate of Kitaev quantum spin liquid proposed recently. We found a spin glass and antiferromagnetic ground states depending on Na stoichiometry, signifying not only the importance of Na vacancy control but also strong frustration in Na3Co2SbO6. Despite its classical ground state, the field-dependent magnetic susceptibility shows remarkable scaling collapse with a single critical exponent, which can be interpreted as evidence of quantum criticality. Its electronic ground state and derived spin Hamiltonian from spectroscopies are consistent with the predicted Kitaev model. Our work provides a unique route to the realization and utilization of Kitaev quantum spin liquid

Preparation of large Cu3Sn single crystal by Czochralski method

Cu3Sn was recently predicted to host topological Dirac fermions, but related research is still in its infancy. The growth of large and high-quality Cu3Sn single crystals is, therefore, highly desired to investigate the possible topological properties. In this work, we report the single crystal growth of Cu3Sn by Czochralski (CZ) method. Crystal structure, chemical composition, and transport properties of Cu3Sn single crystals were analyzed to verify the crystal quality. Notably, compared to the mm-sized crystals from a molten Sn flux, the cm-sized crystals obtained by the CZ method are free from contamination from flux materials, paving the way for the follow-up works

Recent Progress in Stretchable Batteries for Wearable Electronics

With the rapidly approaching implementation of wearable electronic devices such as implantable devices, stretchable sensors, and healthcare devices, stretchable power sources have aroused worldwide attention as a key component in this emerging field. Among stretchable power sources, batteries, which store electrical energy through redox reactions during charge/discharge processes, are an attractive candidate because of their high energy density, high output voltage, and long-term stability. In recent years, extensive efforts have been devoted to developing new materials and innovative structural designs for stretchable batteries. This review covers the latest advances in stretchable batteries, focusing on advanced stretchable materials and their design strategies. First, we provide a detailed overview of the materials aspects of components in a stretchable battery, including electrode materials, solid-state electrolytes, and stretchable separator membranes. Second, we provide an overview on various structural engineering strategies to impart stretchability to batteries (i.e., wavy/buckling structures, island-bridge structures, and origami/kirigami structures). Third, we summarize recently reported developments in stretchable batteries based on various chemistries, including Li-based batteries, multivalent-based batteries, and metal-air batteries. Finally, we discuss the future perspectives and remaining challenges toward the practical application of stretchable batteries with reliable mechanical robustness and stable electro-chemical performance under a physical strain

Additional file 4: Figure S1. of Detection of genetic variation using dual-labeled peptide nucleic acid (PNA) probe-based melting point analysis

Real-time PCR run information. Melting point analysis and/or PCR amplification signals were conducted by specific real-time PCR condition. A) Direct analysis of PNA probe Tm value using fluorescence melting point analysis (FMCA) with synthetic oligonucleotides. B) Hetero-Type SNP detection with PNA-Based FMCA. C) Multiple mutation detection in a short target region. D) Quantitative analysis of PNA-based FMCA. (PNG 414 kb

Stand-Alone Intrinsically Stretchable Electronic Device Platform Powered by Stretchable Rechargeable Battery

Stretchable electronics have been considered a key technology in wearable and implantable medical devices. Although substantial advances have been made in key stretchable components, a stretchable electronic platform that integrates a stretchable power source and a stretchable printed circuit board (SPCB) has been a great challenge. Here, an intrinsically stretchable electronic device platform powered by a stretchable film battery is proposed so that the platform can be used as a stand-alone. The stretchable battery is used as a substrate for manufacturing device platforms where SPCB is printed and directly connected through via holes, thereby enabling an increase in integrated devices density. To achieve an intrinsically stretchable battery and high-performance circuit board, a novel concept of stretchable, self-healable, and pressure-sensitive polymer composite is designed. The platform is water-proof and maintains its stable electrical performance under extreme physical deformations. As a proof of concept, the integration of light-emitting diodes on the platform that can operate at large biaxial strain (125%) underwater is demonstrated

Design of a Janus-Faced Electrode for Highly Stretchable Zinc-Silver Rechargeable Batteries

One of the biggest challenges facing the development of comfortable wearable electronics is the fabrication of stretchable power sources, which are inherently safe and can maintain their electrochemical performance under mechanical elongation. Zinc-silver batteries based on water-based chemistry have been investigated as viable power supply candidates, owing to their high energy/power density and safety. However, this type of batteries requires a new electrode that can guarantee both high elasticity and stable cycling characteristics of the battery. Here, stretchable zinc-silver rechargeable batteries based on a Janus-faced electrode, which is a single electrode that comprises a cathode and an anode, are proposed. The Janus-faced electrode exhibits good mechanical robustness (200 cycles at 200% strain) and retains a high electrical conductivity in the elongated state (2.1 omega at 100% strain). A proof-of-concept stretchable zinc-silver battery based on the Janus-faced electrode is fabricated to demonstrate the outstanding long-term cyclability (capacity retentions of approximate to 90% after 200 cycles), owing to the prevention of short circuit from the zinc dendrite by the unique electrode configuration. Further, the proposed stretchable zinc-silver batteries can deliver a stable electrochemical performance even under a 200% strain while maintaining their functional properties

Fully Elastic Conductive Films from Viscoelastic Composites

We investigated, for the first time, the conditions where a thermoplastic conductive composite can exhibit completely reversible stretchability at high elongational strains (epsilon = 1.8). We studied a composite of Au nanosheets and a polystyrene-block-polybutadiene-block-polystyrene block copolymer as an example. The composite had an outstandingly low sheet resistance (0.45 Omega/sq). We found that when a thin thermoplastic composite film is placed on a relatively thicker chemically cross-linked elastomer film, it can follow the reversible elastic behavior of the bottom elastomer. Such elasticity comes from the restoration of the block copolymer microstructure. The strong adhesion of the thermoplastic polymer to the metallic fillers is advantageous in the fabrication of mechanically robust, highly conductive, stretchable electrodes. The chemical stability of the Au composite was used to fabricate high luminescence, stretchable electrochemiluminescence displays with a conventional top-bottom electrode setup and with a horizontal electrode setup

Electroactive 1T-MoS2 Fluoroelastomer Ink for Intrinsically Stretchable Solid-State In-Plane Supercapacitors

Full advantage of stretchable electronic devices can be taken when utilizing an intrinsically stretchable power source. High-performance stretchable supercapacitors with a simple structure and solid-state operation are good power sources for stretchable electronics. This study suggests a new type of intrinsically stretchable, printable, electroactive ink consisting of 1T-MoS2 and a fluoroelastomer (FE). The active material (1T-MoS2/FE) is made by fluorinating the metallic-phase MoS2 (1T-MoS2) nanosheets with the FE under high-power ultra-sonication. The MoS2 in the 1T-MoS2/FE has unconventional crystal structures in which the stable cubic (1T) and distorted 2H structures were mixed. The printed line of the 1T-MoS2/FE on the porous stretchable Au collector electrodes is intrinsically stretchable at more than epsilon = 50% and has good specific capacitance (28 mF cm(-2) at 0.2 mA cm(-2)) and energy density (3.15 mWh cm(-3)). The in-plane all-solid-state stretchable supercapacitor is stretchable at epsilon = 40% and retains its relative capacity (C/C-o) by 80%. This printable device platform potentially opens up the in-plane fabrication of stretchable micro-supercapacitor devices for wearable electronic applications