Significance Point-of-care thermal management (e.g., joule heating, passive cooling) shows promising applications in body temperature regulations, which can improve human comfort and reduce energy consumption. On-skin electronics with joule-heating elements have been reported. However, the research of making on-skin passive-cooling functionalities is still rare. By using multiscale porous polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene as supporting substrates, we developed...

Dense single-phase BiFeO3 and Bi0.9Ho0.1FeO3 ceramics were prepared by the solid-state reaction method. With Ho doping, remnant polarization of was enhanced switching characteristics improved at low electric fields. doping increased breakdown voltage with a reduction leakage current while mitigating high These results can explain conflicting findings regarding effects rare-earth on polarization. exhibited peculiar double hysteresis looplike magnetization-magnetic field curves much...

GaAs-AlxGa1–xAs (AlGaAs) core–shell nanowires show great promise for nanoscale electronic and optoelectronic devices, but the application of these nonplanar heterostructures in devices requires improved understanding control alloy composition interfaces. Multiple researchers have observed sharp emission lines unknown origin below AlGaAs band edge photoluminescence (PL) spectra nanowires; point defects, fluctuations, self-assembled quantum dots been put forward as candidate structures. Here...

The sequential infiltration synthesis (SIS) of group 13 indium and gallium oxides (In2O3 Ga2O3) into poly(methyl methacrylate) (PMMA) thin films is demonstrated using trimethylindium (TMIn) trimethylgallium (TMGa), respectively, with water. In situ Fourier transform infrared (FTIR) spectroscopy reveals that these metal alkyl precursors reversibly associate the carbonyl groups PMMA in analogy to trimethylaluminum (TMAl), however, significantly lower affinity. This have important kinetic...

Strong surface and impurity scattering in III–V semiconductor-based nanowires (NW) degrade the performance of electronic devices, requiring refined concepts for controlling charge carrier conductivity. Here, we demonstrate remote Si delta (δ)-doping radial GaAs-AlGaAs core–shell NWs that unambiguously exhibit a strongly confined electron gas with enhanced low-temperature field-effect mobilities up to 5 × 103 cm2 V–1 s–1. The spatial separation between high-mobility free at NW interface...

Impurities in semiconductors, for example, lead-based hybrid perovskites, have a major influence on their performance as photovoltaic (PV) light absorbers. While impurities could create harmful trap states that lead to nonradiative recombination of charge carriers and adversely affect PV efficiency, they also potentially increase absorption via midgap energy levels act stepping stones subgap photons or introduce doping. To unearth trends impurity states, we use first principles density...

Sequential infiltration synthesis (SIS) is a route to the precision deposition of inorganic solids in analogy atomic layer but occurs within (vs upon) soft material template. SIS has enabled exquisite nanoscale morphological complexity various oxides through selective nucleation block copolymers templates. However, earliest stages growth remain unresolved, including structure nuclei and evolution local coordination environments, before after polymer template removal. We employed In K-edge...

We propose layer-by-layer growth mechanisms to account for planar defect generation leading kinked polytype nanowires. Cs-corrected scanning transmission electron microscopy enabled identification of stacking sequences distinct bands found in nanowires, and Raman spectroscopy was used distinguish nanowires from twinned containing only the 3C diamond cubic phase. The faceting atomic-scale structures are compared with those develop a common model linking nucleation pinning nanowire morphology

We present a new method for high-resolution nanoscale magnetic resonance imaging (nano-MRI) that combines the high spin sensitivity of nanowire-based detection with high-spectral-resolution nuclear (NMR) spectroscopy. Using incorporates average Hamiltonian theory into optimal control pulse engineering, we demonstrate NMR pulses achieve high-fidelity quantum spins in nanometer-scale ensembles. apply this capability to perform dynamical decoupling experiments factor 500 reduction proton-spin...

Abstract Tailoring the emission spectra of a thermophotovoltaic (TPV) emitter away from that blackbody has potential to minimize transmission and thermalization loss in photovoltaic receiver. Selective TPV emitters can lead solar energy conversion with efficiency greater than Shockley–Queisser limit facilitate generation useful waste heat. A new design is introduced radically tune thermal leverages interplay between two resonant phenomena simple planar nanostructures—absorption weakly...

Abstract Makers of point‐of‐care devices and wearable diagnostics prefer flexible electrodes over conventional electrodes. In this study, a electrode platform is introduced with WS 2 /graphene heterostructure on polyimide (WGP) for the concurrent selective determination dopamine serotonin. The WGP fabricated directly via plasma‐enhanced chemical vapor deposition (PECVD) at 150 °C substrate. Owing to limitations existing fabrication methods from physical transfer or hydrothermal methods, many...

Modulation-doped III–V semiconductor nanowire (NW) heterostructures have recently emerged as promising candidates to host high-mobility electron channels for future high-frequency, low-energy transistor technologies. The one-dimensional geometry of NWs also makes them attractive studying quantum confinement effects. Here, we report correlated investigations into the discrete electronic sub-band structure confined electrons in channel Si δ-doped GaAs−GaAs/AlAs core−superlattice NW and...

Probing localized alloy fluctuations and controlling them by growth kinetics have been relatively limited so far in nanoscale structures such as semiconductor nanowires (NWs). Here, we demonstrate the tuning of molecular beam epitaxially grown GaAs-AlGaAs core-shell NWs modifications shell temperature, investigated correlated micro-photoluminescence, scanning transmission electron microscopy, atom probe tomography. By reducing temperature from T > 600 °C to below 400 °C, find a strong...

Lead halide perovskites present a versatile class of solution-processable semiconductors with highly tunable bandgaps that span ultraviolet, visible, and near-infrared portions the spectrum. We explore phase-separated chloride iodide lead perovskite mixtures as candidate materials for intermediate band applications in future photovoltaics. X-ray diffraction scanning electron microscopy reveal deposition precursor solutions across MAPbCl3/MAPbI3 composition space affords quasi-epitaxial...

The efficiency of a thermophotovoltaic (TPV) system depends critically upon the spectral selectivity and stability an emitter, which may operate most effectively at temperatures in excess 1000 °C. We computationally design experimentally demonstrate novel selective emitter based on multilayer nanostructures, robust to off-normal emission angles. A computational search material temperature compatibility space simple designs motivates new classes identifies several promising nanostructure for...

Sequential infiltration synthesis (SIS) is a vapor phase synthetic method that enables the selective nucleation and growth of metal oxides within polymer volumes. The expanding palette SIS materials process designs tunability resulting material properties. We derive porous indium oxide thin films from using trimethyl H2O2 in polymethyl methacrylate observe strong effect post-deposition processing, which affords 7 orders magnitude electrical resistivity. While as-deposited hybrid...

Ternary III–V alloys of tunable bandgap are a foundation for engineering advanced optoelectronic devices based on quantum-confined structures including quantum wells, nanowires, and dots. In this context, core–shell nanowires provide useful geometric degrees freedom in heterostructure design, but alloy segregation is frequently observed epitaxial shells even the absence interface strain. High-resolution scanning transmission electron microscopy laser-assisted atom probe tomography were used...

Core-shell semiconductor nanowires (NW) with internal quantum heterostructures are amongst the most complex nanostructured materials to be explored for assessing ultimate capabilities of diverse ultrahigh-resolution imaging techniques. To probe structure and composition these in their native environment minimal damage sample preparation calls high-resolution electron or ion microscopy methods, which have not yet been tested on such classes ultrasmall nanostructures. Here, we demonstrate that...

Titanium nitride (TiN) is a unique refractory plasmonic material, the nanocomposites and alloys of which provide further opportunities to tailor its optical photonic properties. We prepare TiAlN films continuously variable compositions through systematic variation TiN versus AlN cycle ratio in plasma-enhanced atomic layer deposition (PEALD) investigate resulting thin-film composition, crystallinity, The properties are not simple linear combinations films, exhibit distinct metallic dielectric...

Only a few iron precursors that can be used in the atomic layer deposition (ALD) of oxides have been examined thus far. This study aimed to compare various properties FeOx thin films deposited using thermal ALD and plasma-enhanced (PEALD) evaluate advantages disadvantages bis(N,N'-di-butylacetamidinato)iron(II) as an Fe precursor ALD. The PEALD bisamidinate has not yet reported. Compared with films, exhibited improved terms surface roughness, film density, crystallinity after they were...

Abstract Sequential infiltration synthesis (SIS) is an emerging technique for producing inorganic–organic hybrid materials and templated inorganic nanomaterials. The application space SIS expanding rapidly in areas such as lithography, filtration, photovoltaics, antireflection, triboelectricity, but not the field of electrochemistry. This study performs fabrication porous, transparent, electrically conductive films indium zinc oxide (IZO) to evaluate their potential electrode electrochemical...

The modulation between different doping species required to produce a diode in VLS-grown nanowires (NWs) yields complex profile, both axially and radially, gradual junction at the interface. We present detailed analysis of dopant distribution around junction. By combining surface potential measurements, performed by KPFM, with finite element simulations, we show that highly doped (5 × 1019 cm–3) shell surrounding NW can screen junction's built voltage thickness as low 3 nm. comparing NWs...

Sequential infiltration synthesis (SIS) is a novel technique for fabricating organic-inorganic hybrid materials and porous inorganic by leveraging the diffusion of gas-phase precursors into polymer matrix chemical reactions between to synthesize therein. This study aims obtain fundamental understanding physicochemical mechanisms behind SIS, from which SIS processing conditions are rationally designed precise control over distribution metal oxides. Herein, in situ FTIR spectroscopy was...