Soft, deformable electronic devices provide the means to monitor physiological information and health conditions for disease diagnostics. However, their practical utility is limited due to the lack ...of intrinsical thermal switching for mechanically transformative adaptability and self‐healing capability against mechanical damages. Here, the design concepts, materials and physics, manufacturing approaches, and application opportunities of self‐healing, reconfigurable, thermal‐switching device platforms based on hyperbranched polymers and biphasic liquid metal are reported. The former provides excellent self‐healing performance and unique tunable stiffness and adhesion regulated by temperature for the on‐skin switch, whereas the latter results in liquid metal circuits with extreme stretchability (>900%) and high conductivity (3.40 × 104 S cm−1), as well as simple recycling capability. Triggered by the increased temperature from the skin surface, a multifunctional device platform can conveniently conform and strongly adhere to the hierarchically textured skin surface for non‐invasive, continuous, comfortable health monitoring. Additionally, the self‐healing and adhesive characteristics allow multiple multifunctional circuit components to assemble and completely wrap on 3D curvilinear surfaces. Together, the design, manufacturing, and proof‐of‐concept demonstration of the self‐healing, transformative, and self‐assembled electronics open up new opportunities for robust soft deformable devices, smart robotics, prosthetics, and Internet‐of‐Things, and human–machine interfaces on irregular surfaces.
Printing solid–liquid biphasic liquid metal patterns on the hygroscopic hyperbranched polymer substrate demonstrates a self‐healing, reconfigurable device platform with thermal‐switching stiffness and adhesion. Triggered by the increased temperature, the device platform conforms and adheres to the textured skin or other 3D curvilinear surfaces can provide an integrated remote monitoring system for non‐invasive, continuous, long‐term health monitoring of people and structures.
Formaldehyde is a strong-smelling, colorless, excitant gas that is carcinogenic to humans. It is frequently used in the interior of decorative materials such as wood paneling and carpets. Several ...epidemiological studies have shown that the increasing incidence of nasal and lung cancer is due to exposure to environmental formaldehyde. Thus, the rapid detection of formaldehyde with high sensitivity is vitally important for environmental monitoring and clinical diagnosis. Surface-enhanced Raman scattering (SERS) is an analytical technique that can provide fingerprint information on target materials with a sensitivity even down to the single-molecule level. However, formaldehyde molecules have a low cross section for Raman scattering and extremely weak analyte–metal interactions, and are thus scarcely detectable with conventional SERS technology. In this paper, a porous zeolitic imidazolate framework-8 (ZIF-8) shell layer was grown in situ on gold nanostars (AuNSs) for capturing and altering the route taken by formaldehyde molecules. Compared with current SERS detection methods, these as-synthesized core–shell AuNS@ZIF-8 nanocomposites with special apertures can cause formaldehyde molecules to pass through the ZIF-8 channels to the metal surface. With the help of ZIF-8 shell layers, the SERS-active AuNS@ZIF-8 substrates display extremely high sensitivity to formaldehyde molecules, with the lowest detection level almost at parts per billion (ppb). This study may therefore provide the basis for a reliable SERS strategy for detecting small molecules, especially gas samples.
Recently, chiral hybrid organic-inorganic perovskites (HOIPs) are drawing wide attention due to their intrinsic noncentrosymmetric structures which result in fascinating properties such as ...ferroelectronics and second-order nonlinear optics (NLO). However, previous research mainly focused on chiral lead-based halide perovskites ignoring that the toxic Pb element is harmful to humans and the environment. Herein, we successfully synthesized block-like (
R
-/
S
-NEA)
2
CuCl
4
(NEA = 1-naphthylethylamine) and needle-like (
R
-/
S
-CYHEA)
6
Cu
3
Cl
12
(CYHEA = 1-cyclohexylethylamine) single crystals, which crystallize in the Sohncke
P
2
1
and
I
2 space group, respectively. Each pair of chiral perovskite enantiomers shows mirror circular dichroism (CD) signals. The thin films show an efficient second harmonic generation (SHG) response and the NLO coefficients of (
R
-NEA)
2
CuCl
4
and (
R
-CYHEA)
6
Cu
3
Cl
12
are 11.74 and 3.04 pm V
−1
, respectively, under 920 nm excitation with Y-cut quartz as a reference, which shows that the chiral amine has a significant effect on the SHG behavior. The high SHG response of (
R
-NEA)
2
CuCl
4
is perhaps due to the rigidity of the aromatic amine, which leads to highly asymmetrical space groups. Our results provide guidelines for designing and tuning the SHG response in chiral HOIPs.
Copper-based hybrid organic-inorganic perovskites with chiral amines, (
R
-NEA)
2
CuCl
4
(NEA = 1-naphthylethylamine) and (
R
-CYHEA)
6
Cu
3
Cl
12
, show second harmonic generation.
Chiral metal halides have shown great potential for application in next generation nonlinear optical (NLO) devices owing to their intrinsic non-centrosymmetry. However, the structures and properties ...of chiral hybrid indium halides have been rarely reported, especially when it comes to second-harmonic generation (SHG) in NLO. In this work, we have synthesized a pair of new zero-dimensional (0D) chiral hybrid indium halides, (
R
-MPEA)
6
InCl
9
and (
S
-MPEA)
6
InCl
9
, and studied their NLO properties. The as-prepared chiral hybrid indium halides crystallize in non-centrosymmetric
P
3
2
21 and
P
3
1
21 space groups, respectively. NLO studies show that 0D chiral hybrid indium halide crystals exhibit strong SHG responses with high polarization ratio and high laser damage threshold (LDT). This work enriches the family of chiral hybrid metal halide materials and offers a feasible strategy for the targeted design and synthesis of intrinsically non-centrosymmetric metal halide materials for NLO applications.
New types of chiral 0D hybrid indium halides, (
R
-/
S
-MPEA)
6
InCl
9
, have been constructed with high efficiency SHG response, high polarization ratio (93.1%) and high laser damage threshold (3.82 mJ cm
2
at 800 nm).
To realize high-energy-density Li metal batteries at low temperatures, a new electrolyte is needed to solve the high-voltage compatibility and fast lithium-ion de-solvation process. A gel polymer ...electrolyte with a small-molecular-weight polymer is widely investigated by combining the merits of a solid polymer electrolyte (SPE) and liquid electrolyte (LE). Herein, we present a new gel polymer electrolyte (P-DOL) by the lithium difluoro(oxalate)borate (LiDFOB)-initiated polymerization process using 1,3-dioxolane (DOL) as a monomer solvent. The P-DOL presents excellent ionic conductivity (1.12 × 10−4 S cm−1) at −20 °C, with an oxidation potential of 4.8 V. The Li‖LiCoO2 cell stably cycled at 4.3 V under room temperature, with a discharge capacity of 130 mAh g−1 at 0.5 C and a capacity retention rate of 86.4% after 50 cycles. Moreover, a high-Ni-content LiNi0.8Co0.1Mn0.1O2 (NCM811) cell can steadily run for 120 cycles at −20 °C, with a capacity retention of 88.4%. The underlying mechanism of high-voltage compatibility originates from the dense and robust B- and F-rich cathode interface layer (CEI) formed at the cathode interface. Our report will shed light on the real application of Li metal batteries under all-climate conditions in the future.
Chiral hybrid organic–inorganic metal halides (HOMHs) offer an ideal platform for the advancement of second‐order nonlinear optical (NLO) materials owing to their inherent noncentrosymmetric ...structures. The enhancement of optical nonlinearity of chiral HOMHs could be achieved by matching the free exciton and/or self‐trapped exciton energy levels with desired NLO frequencies. However, the current scarcity of resonance modes and low resonance ratio hamper the further improvements of NLO performance. Herein, we propose a new resonant channel of charge transfer (CT) excited states from metal halide polyhedra to organic ligand to boost the second‐order optical nonlinearity of chiral HOMHs. The model lead halide (C7H10N)PbBr3 (C7H10N=1‐ethylpyridinium) exhibits a drastically enhanced second harmonic generation in resonance to the deep CT exciton energy, with intensity of up to 111.0 times that of KDP and 10.9 times that of urea. The effective NLO coefficient has been determined to be as high as ~40.2 pm V−1, balanced with a large polarization ratio and high laser damage threshold. This work highlights the contribution of organic ligands in the construction of a resonant channel for enhancing second‐order NLO coefficients of metal halides, and thus provides guidelines for designing new chiral HOMHs materials for advanced nonlinear photonic applications.
The metal octahedra to ligand charge transfer excitons of chiral metal halides have been demonstrated to serve as a new resonant channel with an appropriate resonant energy level to boost second‐order optical nonlinearity. Ultimately, these single crystals exhibit remarkably resonant enhanced SHG signals, of one order of magnitude higher than that of urea and two orders of magnitude higher than that of KDP.
Chiral hybrid organic−inorganic perovskites (HOIPs) with intrinsic noncentrosymmetry have shown great potentials for chiroptoelectronic applications including second‐order nonlinear optics (NLO). ...Ideal NLO materials should simultaneously feature a large NLO coefficient, wide optical transparency, high laser damage threshold, and physicochemical stability. However, the development of applicable second‐order NLO materials has been largely restricted due to their strict requirement on structural noncentrosymmetry. Here, chiral amino acids abundant in nature have been adopted to synthesize hybrid lead halide perovskites (D‐/L‐Pro)PbI3·H2O (Pro = Proline) with resonance enhanced second‐harmonic generation (SHG). Their crystals feature balanced NLO performances with a large NLO coefficient, wide transparent region, high laser damage threshold, and high polarization ratio. This work demonstrates the promise of naturally abundant amino acids for the construction of hybrid chiral metal halide perovskites for next generation optoelectronic materials.
Proline hybrid lead halide perovskites (D‐/L‐Pro)PbI3·H2O have been constructed, which exhibit resonance enhanced second‐order nonlinear optical properties, with a large nonlinear optical coefficient, wide transparent region, high laser damage threshold, and high polarization ratio, which demonstrate the promise of naturally abundant amino acids for the construction of hybrid chiral metal halide perovskites for next generation chiroptoelectronic materials.
Limited Devonian magmatic record in northern West Junggar leads to contrasting models on its tectonic evolution. In this study, we conducted LA‐ICP‐MS U‐Pb dating on detrital zircons of two ...sandstones from the Hebukesaier Formation in the Shaerbuerti Mountains. Detrital zircons with oscillatory zoning are characterized by high Th/U (> 0.3) and low La/Yb (< 0.15), indicating their magmatic origin. The youngest zircon ages of two samples are 402 ± 2 Ma and 406 ± 2 Ma, respectively, suggesting that the Hebukesaier Formation was deposited at the Early Devonian. Detrital zircon age patterns show single peaks (at ca. 424 Ma, n = 157), which indicates that these clastics were likely proximal accumulation after short distance transportation. Provenance of the Hebukesaier Formation was the Xiemisitai and Shaerbuerti Mountains. Detrital zircon ages range from 481 Ma to 395 Ma, which indicates that there was relatively continuous Early Paleozoic magmatism in the Xiemisitai and Shaerbuerti Mountains since the Early Ordovician. Age spectrums of sampled detrital zircons are distinct from those of Lower Devonian strata either in southern West Junggar or in East Junggar, which implies for individual tectonic evolution of northern West Junggar. We favor that Lower Devonian Hebukesaier Formation was developed in a fore–arc setting due to the northward subduction of the Junggar–Balkhash Ocean.
Organic π-conjugated materials have demonstrated superior nonlinear optical (NLO) performance and serve as ideal candidates for photonic devices. However, the design of organic NLO materials with ...well-defined architectures and highly efficient second-order NLO properties remains a significant challenge. Here, pyridine groups with different N-substitution positions have been incorporated into the fluorenone skeleton to obtain target compounds 3-DPyFO and 4-DPyFO with modulated intermolecular interactions and self-assembly behaviors. Noncentrosymmetric 3-DPyFO-α exhibits thermal-induced phase transition and unusual multi-response fluorescence including thermochromic and mechanochromic luminescence. Meanwhile, 4-DPyFO-α shows highly efficient second- and third-order NLO effects, along with a resonance enhancement of second harmonic generation (SHG) and two-photon excited fluorescence (TPF). This study on NLO properties of pyridine functionalized fluorenone derivatives will enrich the fluorenone based NLO materials for photonic device applications.
A pair of pyridine based fluorenone derivatives with highly efficient second- and third-order nonlinear optical effects have been synthesized.
Chiral hybrid organic–inorganic metal halides (HOMHs) offer an ideal platform for the advancement of second‐order nonlinear optical (NLO) materials owing to their inherent noncentrosymmetric ...structures. The enhancement of optical nonlinearity of chiral HOMHs could be achieved by matching the free exciton and/or self‐trapped exciton energy levels with desired NLO frequencies. However, the current scarcity of resonance modes and low resonance ratio hamper the further improvements of NLO performance. Herein, we propose a new resonant channel of charge transfer (CT) excited states from metal halide polyhedra to organic ligand to boost the second‐order optical nonlinearity of chiral HOMHs. The model lead halide (C7H10N)PbBr3 (C7H10N=1‐ethylpyridinium) exhibits a drastically enhanced second harmonic generation in resonance to the deep CT exciton energy, with intensity of up to 111.0 times that of KDP and 10.9 times that of urea. The effective NLO coefficient has been determined to be as high as ~40.2 pm V−1, balanced with a large polarization ratio and high laser damage threshold. This work highlights the contribution of organic ligands in the construction of a resonant channel for enhancing second‐order NLO coefficients of metal halides, and thus provides guidelines for designing new chiral HOMHs materials for advanced nonlinear photonic applications.
The metal octahedra to ligand charge transfer excitons of chiral metal halides have been demonstrated to serve as a new resonant channel with an appropriate resonant energy level to boost second‐order optical nonlinearity. Ultimately, these single crystals exhibit remarkably resonant enhanced SHG signals, of one order of magnitude higher than that of urea and two orders of magnitude higher than that of KDP.
