All‐solid‐state (ASS) lithium metal batteries (LMBs) are considered the most promising next‐generation batteries due to their superior safety and high projected energy density. To access the ...practically desired high energy density of ASS LMBs, an ultrathin solid‐state electrolyte (SSE) film with fast ion‐transport capability presents as an irreplaceable component to reduce the proportion of inactive materials in ASS batteries. In this contribution, an ultrathin (60 µm), flexible, and free‐standing argyrodite (Li6PS5Cl) SSE film is designed through a self‐limited strategy. A chemically compatible cellulose membrane is employed as the self‐limiting skeleton that not only defined the thinness of the sulfide SSE film but also strengthened its mechanical properties. The ionic conductivity of the SSE film reaches up to 6.3 × 10−3 S cm−1 at room temperature, enabling rapid lithium‐ion transportation. The self‐limited SSE thin films are evaluated in various ASS LMBs with different types of cathode (sulfur and lithium titanate) and anode materials (lithium and lithium‐indium alloy) at both mold‐cell and pouch‐cell levels, demonstrating a stable performance and high‐rate capability. This study provides a general strategy for the rational design of an SSE thin film towards high‐energy‐density ASS batteries.
An ultrathin, flexible, and free‐standing argyrodite solid‐state electrolyte film is designed through a self‐limited strategy. The ionic conductivity of the SSE film reaches up to 6.3 × 10−3 S cm−1 at room temperature, enabling rapid lithium‐ion transportation in all‐solid‐state batteries.
2D covalent organic frameworks (2D COFs) are a unique materials platform that combines covalent connectivity, structural regularity, and molecularly precise porosity. However, 2D COFs typically form ...insoluble aggregates, thus limiting their processing via additive manufacturing techniques. In this work, colloidal suspensions of boronate‐ester‐linked 2D COFs are used as a spray‐coating ink to produce large‐area 2D COF thin films. This method is synthetically general, with five different 2D COFs prepared as colloidal inks and subsequently spray‐coated onto a diverse range of substrates. Moreover, this approach enables the deposition of multiple 2D COF materials simultaneously, which is not possible by polymerizing COFs on substrates directly. When combined with stencil masks, spray‐coated 2D COFs are rapidly deposited as thin films larger than 200 cm2 with line resolutions below 50 µm. To demonstrate that this deposition scheme preserves the desirable attributes of 2D COFs, spray‐coated 2D COF thin films are incorporated as the active material in acoustic sensors. These 2D‐COF‐based sensors have a 10 ppb limit‐of‐quantification for trimethylamine, which places them among the most sensitive sensors for meat and seafood spoilage. Overall, this work establishes a scalable additive manufacturing technique that enables the integration of 2D COFs into thin‐film device architectures.
High‐resolution, large‐scale fabrication of 2D covalent organic framework (COF) thin films is achieved by spray‐coating colloidal inks of these materials. Using this additive manufacturing approach, 2D COF thin films are integrated into acoustic sensing platforms. These sensors achieve superlative detection of volatile amines including a limit‐of‐quantification of 10 ppb for trimethylamine, which is a target analyte for the detection of food spoilage.
Vanadium dioxide (VOsub.2) with semiconductor-metal phase transition characteristics has presented great application potential in various optoelectrical smart devices. However, the preparation of ...doped VOsub.2 film with a lower phase transition threshold on Si substrate needs more investigation for the exploration of silicon-based VOsub.2 devices. In this work, the VOsub.2 films doped with different contents of W element were fabricated on high-purity Si substrate, assisted with a post-annealing process. The films exhibited good crystallinity and uniform thickness. The X-ray diffraction and X-ray photoelectron spectroscopy characterizations illustrated that W element can be doped into the lattice of VOsub.2 and lead to small lattice distortion. In turn, the in situ FT-IR measurements indicated that the phase transition temperature of the VOsub.2 films can be decreased continuously with W doping content. Simultaneously, the doping would lead to largely enhanced conductivity in the film, which results in reduced optical transmittance. This work provides significant insights into the design of doped VOsub.2 films for silicon-based devices.
Molybdenum oxide (MoO.sub.x) films had been grown by using plasma-enhanced atomic layer deposition (PEALD) with Mo(CO).sub.6 precursor and O.sub.2 plasma reactant in a substrate temperature range of ...150-275 °C. The effect of substrate temperature on the chemical, optical, surface morphological, and structural properties of the MoO.sub.x thin films was explored systematically. The substrate temperature performed a significant role in depositing MoO.sub.x films and three kinds of different precursor reaction mechanisms of PEALD-MoO.sub.x thin films handled by substrate temperature were presented firstly and illustrated comprehensively. The growth of amorphous MoO.sub.x film was observed between 150 and 175 °C. Moreover, an obvious transition to polycrystalline deposition was demonstrated for the deposition temperatures at 225 °C and higher. Both Mo.sup.6+ and Mo.sup.5+ valence states existed in all prepared MoO.sub.x films, which inferred the deficient lattice oxygen in the films. And the proportion of non-lattice oxygen reduced with the increasing deposition temperature. The elaboration of deposition mechanism of PEALD-MoO.sub.x films provides a guideline for the preparation of high-quality MoO.sub.x films.
The discovery of high mobility p-type two-dimensional beta-tellurite (beta-TeO.sub.2) has led to an increasing interest in tellurium oxide-related polymorphs. Bulk TeO.sub.2 is known to exist in ...three polymorphs (alpha-, beta-, and gamma-TeO.sub.2), all of which exhibit wide bandgaps. By utilizing the interfacial interactions, we successfully synthesized a new polymorph of TeO.sub.2 with a rutile structure on a tetragonal FeTe surface via soft surface oxidation. Irrespective of the film thickness, the rutile TeO.sub.2 exhibited a metallic Fermi surface, as revealed by low-temperature scanning tunneling spectroscopy and further confirmed by our theoretical calculations. Striped wrinkles with an apparent lattice shift were observed on large rutile TeO.sub.2 monolayer islands due to lattice distortion. The density of states around the Fermi level accordingly shift from a U-shaped gap to a V-shaped feature. Our synthesis and observation of rutile TeO.sub.2, based on interface engineering and in situ tunneling spectroscopy, can help tune the electronic properties of tellurium oxide in reduced dimensions.
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