Inorganic Semiconductors Research Articles

Photochromism in Sm3+-doped inorganic semiconductor oxide CaBiNb2O9 induced by ultraviolet light irradiation

Photochromism in Sm3+-doped inorganic semiconductor oxide CaBiNb2O9 induced by ultraviolet light irradiation

What Can Chemical Bonding Tell Us about Photoinduced Phase Transition Reactions in Inorganic Semiconductors? Insight from Bismuth-Antimony Selenide.

Photoreactive self-healing semiconductors with suitable bandgaps for solar energy conversion offer an intriguing path to making resilient and low-cost photovoltaic devices through the introduction of a self-recovery path. However, only a few inorganic photovoltaic materials have such quality, and the underlying chemical properties that enable it are unknown, which poses a significant limit to our ability to study and discover new self-healing semiconductors. Recently, we have found that antimony trichalcogenide (Sb2Se3 and Sb2S3) and chalcohalides (e.g., SbSeI) can undergo a reversible photoinduced phase transition (PIPT) in which the structure is restored after photoinduced damage incurs to the materials. This group of materials offer a unique opportunity for studying PIPT and its limits. In particular, this group of materials facilitate the study of functional permutation to specific crystalline sites and to finding the limits of PIPT occurrence, which sheds light on the origin of the PIPT and self-recovery of this class of materials. Using Raman spectroscopy of thin films, and following signature vibrations of transition species, we have found that the PIPT magnitude decays upon gradual BiSb(1) substitution in a Sb2-xBixSe3 homologous series, until nearly one in five Sb ions is substituted with Bi. Then, the PIPT diminishes completely. The homologous series occurs along a transition from covalent to metavalent chemical bonding. By expanding our search, we find that a correlation between bonding type and photoreactivity does exist but conclude that it is an insufficient condition. Instead, we suggest, based on bond order and additional DFT calculations, that sufficient bonding states at the bottom of the conduction band are also required. This joint experimental and computational study pushes the limits of designing self-healing inorganic semiconductors for various applications and provides tools for further expansion.

Tuning direct-written terahertz metadevices with organic mixed ion-electron conductors

In the past decade, organic mixed ion-electron conductors have been successfully adopted in innovative bioelectronic, neuromorphic, and electro-optical technologies, as well as in multiple energy harvesting and printed electronics applications. However, despite the intense research efforts devoted to these materials, organic mixed conductors have not yet found application in electronic/photonic devices operating in key regions of the electromagnetic spectrum, such as the microwave (>5 GHz) and terahertz (0.1-10 THz) ranges. A possible reason for this technological gap is the widespread notion that organic electronic materials are unsuitable for high-frequency applications. In this work, we demonstrate for the first time the utility of high-performance polymer mixed conductors as electro-active tuning layers in reconfigurable terahertz metasurfaces, achieving modulation performances comparable with state-of-the-art inorganic and 2D semiconductors. Through time-domain terahertz spectroscopy, we show that the large conductivity modulations of these polymers, until now probed only at very low frequencies, are effectively preserved in the terahertz range, leading to optimal metadevice reconfigurability. Finally, we leverage the unique processability of organic materials to develop fully direct-written electrically tuneable metasurfaces onto both rigid and flexible substrates, opening new opportunities for the mass-scale realization of flexible and light-weight terahertz optics with unique mechanical characteristics and environmental footprint.

Explainable artificial intelligence for machine learning prediction of bandgap energies

The bandgap is an inherent property of semiconductors and insulators, significantly influencing their electrical and optical characteristics. However, theoretical calculations using the density functional theory (DFT) are time-consuming and underestimate bandgaps. Machine learning offers a promising approach for predicting bandgaps with high precision and high throughput, but its models face the difficulty of being hard to interpret. Hence, an application of explainable artificial intelligence techniques to the bandgap prediction models is necessary to enhance the model's explainability. In our study, we analyzed the support vector regression, gradient boosting regression, and random forest regression models for reproducing the experimental and DFT bandgaps using the permutation feature importance (PFI), the partial dependence plot (PDP), the individual conditional expectation plot, and the accumulated local effects plot. Through PFI, we identified that the average number of electrons forming covalent bonds and the average mass density of the elements within compounds are particularly important features for bandgap prediction models. Furthermore, PDP visualized the dependency relationship between the characteristics of the constituent elements of compounds and the bandgap. Particularly, we revealed that there is a dependency where the bandgap decreases as the average mass density of the elements of compounds increases. This result was then theoretically interpreted based on the atomic structure. These findings provide crucial guidance for selecting promising descriptors in developing high-precision and explainable bandgap prediction models. Furthermore, this research demonstrates the utility of explainable artificial intelligence methods in the efficient exploration of potential inorganic semiconductor materials.

Phenyl-C61-butyric acid methyl ester (PCBM) Nanoparticle Mediated Boasting of Photoelectrochemical and Photocatalytic Properties of Bismuth Vanadate/lead sulphide (BiVO4/PbS) Composite Thin-Film

This work delineates the fabrication and characterization of BiVO4/PbS and BiVO4/PCBM/PbS-based composite heterostructure for visible-light-driven applications, such as pollution remediation, photoelectrochemistry (PEC), and applied bias to photoelectrochemical hydrogen generation efficiency (ABPE). The heterostructured composite was synthesized by a combination of Spin coating (for bismuth vanadate - BiVO4 thin film fabrication and PCBM deposition), and Successive Ionic Layer Absorption and Reaction -SILAR (for lead sulphide - PbS deposition) method and characterized using UV-visible Spectroscopy, time-resolved photoluminescence spectroscopy (TRPL), field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and photoelectrochemistry (PEC) analysis (PEC). The key benefit of incorporation of PCBM nanoparticles in BiVO4/PCBM/PbS was realized through 1) ∼ 70% improvement in the photocurrent density during electrochemistry analysis, 2) ∼ 2.3 times enhancement in ABPE, and 3) ∼ 43% enhancements in ‘rate constant’ towards photocatalytic (methylene blue) degradation compared to BiVO4/PbS. The work shows the benefits of the PCBM-conductive carbon-based electron transport layer as a bridge between two inorganic semiconductors (BiVO4 and PbS) towards enhancing fast electron separation and transport at the interface during visible light irradiation.

Confinement of Z-scheme organic-inorganic heterojunction into mesoporous zeolite for efficient photocatalytic solar fuel generation

Organic-inorganic heterojunction has drawn increasing interest in photocatalytic CO2 reduction (PCR) by immobilizing molecular catalysts on inorganic semiconductors. However, it is difficult to control the size and dispersion of inorganic semiconductors during the assembling process, which restricts the PCR performance due to limited active sites and charge separation efficiency. Herein, we utilized a commercial mesoporous zeolite (SBA-15) to confine TiO2 via an in situ approach followed by assembling with a Co(II) tetra(4-carboxylphenyl) porphyrin (Co-TCPP). As a result, a Z-scheme organic–inorganic heterojunction of TiO2/SBA-15@Co-TCPP was obtained, which demonstrated superior PCR performance among simulated solar light irradiation. The optimized TiO2/SBA-15@Co-TCPP demonstrated improved solar fuel evolution (241.63 μmolco g−1) via PCR process when compared to bulk TiO2 or pristine Co-TCPP. The experiment results and density functional theory (DFT) calculations reveal the superior PCR performance induced by the extended light-harvesting region from the Z-scheme heterojunction, elevated PCR selectivity induced by the hydrophilicity of SBA-15 and molecular Co(II) center, enhanced charge separation owing to the highly dispersed nanosized TiO2 and inner-building electronic field. This work highlights the importance of mesoporous zeolite substrate in control of the PCR activity and selectivity, which hold great potential to develop multiple zeolite-based heterojunctions for efficient solar-driven fuel generation.

Zn/Pt dual-site single-atom driven difunctional superimposition-augmented sonosensitizer for sonodynamic therapy boosted ferroptosis of cancer

Sonodynamic therapy (SDT) as a non-invasive antitumor strategy has been widely concerned. However, the rapid electron (e-) and hole (h+) recombination of traditional inorganic semiconductor sonosensitizers under ultrasonic (US) stimulation greatly limits the production of reactive oxygen species (ROS). Herein, we report a unique Zn/Pt dual-site single-atom driven difunctional superimposition-augmented TiO2-based sonosensitizer (Zn/Pt SATs). Initially, we verify through theoretical calculation that the strongly coupled Zn and Pt atoms can assist electron excitation at the atomic level by increasing electron conductivity and excitation efficiency under US, respectively, thus effectively improving the yield of ROS. Additionally, Zn/Pt SATs can significantly enhance ferroptosis by producing more ROS and sonoexcited holes under US stimuli. Therefore, the establishment of dual-site single-atom system represents an innovative strategy to enhance SDT in cancer model of female mice and provides a typical example for the development of inorganic sonosensitizer in the field of antitumor therapy.

Van der Waals semiconductor InSe plastifies by martensitic transformation.

Inorganic semiconductor materials are crucial for modern technologies, but their brittleness and limited processability hinder the development of flexible, wearable, and miniaturized electronics. The recent discovery of room-temperature plasticity in some inorganic semiconductors offers a promising solution, but the deformation mechanisms remain controversial. Here, we investigate the deformation of indium selenide, a two-dimensional van der Waals semiconductor with substantial plasticity. By developing a machine-learned deep potential, we perform atomistic simulations that capture the deformation features of hexagonal indium selenide upon out-of-plane compression. Unexpectedly, we find that indium selenide plastifies through a martensitic transformation; that is, the layered hexagonal structure is converted to a tetragonal lattice with specific orientation relationship. This observation is corroborated by high-resolution experimental observations and theory. It suggests a change of paradigm, where the design of new plastically deformable inorganic semiconductors can focus on compositions and structures that facilitate phase transformations, going beyond the conventional dislocation slip.

Enhanced photo-fermentative hydrogen production by constructing Rhodobacter capsulatus-ZnO/ZnS hybrid system

This study incorporated ZnO/ZnS nanoparticles with Rhodobacter capsulatus SB1003, forming a hybrid system to promote photo-fermentative hydrogen production. The results indicate that the material’s photocatalytic activity and concentration significantly affected hydrogen yield. The addition of ZnO/ZnS exhibited a more significant auxiliary effect than ZnO and achieved an approximately 30% increase in hydrogen production compared to the control group. ZnO/ZnS enhanced the production of extracellular polymers, thereby strengthening the synergy between the nanomaterials and the bacteria. The photogenerated electrons from ZnO/ZnS were utilized by the photosynthetic bacteria. Furthermore, the activity of nitrogenase was enhanced, resulting in improved hydrogen production performance. This study provides insights into hydrogen production by photosynthetic bacteria with the assistance of inorganic semiconductor nanomaterials.

One‐Step Room Temperature Synthesis of Printable Carbon Quantum Dots Ink for Visual Encryption and High‐Performance Photodetector

AbstractCarbon quantum dots (CQDs) have emerged as promising materials for optoelectronic applications and have garnered much interest as potential competitors to conventional inorganic or hybrid semiconductor quantum dots because of carbon's intrinsic merits of high stability, low cost, and environment‐friendliness. The ability of easy formulation of functional ink of CQDs is necessary for the development of industrial‐scale, reliable, inexpensive printing/coating processes, for its full exploitation in the ever‐growing class of applications in sensors, optoelectronics, and energy storage and conversion. Here a facile one‐step room‐temperature synthesis of printable, fluorescent CQD ink is demonstrated. The as‐synthesized fluorescent CQD ink is used for invisible fingerprint stamps, printing of micro‐patterns, and soft lithographic patterning with a resolution down to 1.5 µm. This functional CQD ink is also used to fabricate a high‐performance CQD‐ZnO heterojunction ultraviolet (UV) photodetector with a photo‐responsivity of 3.85 A W−1, detectivity of 6.78 × 1010 Jones, and an external quantum efficiency (EQE) of 15.3%. The enhanced device performance can be attributed to CQD's high photocurrent generation efficiency and rational combination of the asymmetric electrode materials. This work enables a high‐temperature stable CQD fluorescent ink synthesis method to fulfill the processing requirements of printing and soft lithographic patterning for visual encryption and optoelectronics.

Study on photocatalytic degradation and antibacterial properties of conjugated microporous polymers/TiO2 composite membranes

Conjugated microporous polymers (CMPs) are widely used in the field of photocatalysis due to their unique conjugated structures and various synthesis methods. Herein, we report the design and synthesis of conjugated microporous polymers hollow spheres (CMPs-HS) superhydrophilic modified by acetylcysteine (CMPs-HS-S) and compounded with the inorganic semiconductor material titanium dioxide (CMPs-HS-S/TiO2) for efficient photocatalytic degradation. To facilitate recycling, the composite membrane material was prepared by combining the materials mentioned above with PVDF membrane. The composite membrane materials had good hydrophilic and photocatalytic properties. Under visible light, the degradation rate of tetracycline (TC) (10 mg/L 180 min) reached 90 %, and the bactericidal rates for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were 89 % and 99.99 %, respectively. The efficient photocatalytic performance of the composite membranes could be attributed to the hollow sphere structure of CMPs and the role of TiO2 as a photogenic electron transfer platform. Additionally, the hydrophilicity of the membrane also helped to accelerate the occurrence of photocatalytic reactions. After electron paramagnetic resonance (EPR) detection, h+, 1O2 and O2− were proved to be important reactive substances, which played a major role in degradation. These studies reflect the versatility of CMPs-based photocatalysts and provide a new idea for the future development of CMPs-based photocatalysts.

Solid-Solution MXenes: Synthesis, Properties, and Applications.

ConspectusMXenes, among other two-dimensional (2D) materials such as graphene, hexagonal BN, transition metal dichalcogenides (TMDs), 2D metal-organic frameworks (MOFs), and covalent organic frameworks (COFs), are the fastest growing class discovered thus far. The general formula of MXenes is Mn+1XnTx, where M, X, and Tx represent an early transition metal (Ti, V, Nb, Mo, etc.), C and/or N, and the surface functional groups (typically, O, OH, F, Cl), respectively, and n can be between 1 and 4. MXenes as a class of materials have extraordinary properties, such as high electrical conductivity, nonlinear optical properties, solution processability, scalability and ease of synthesis, redox capability, and tunable surface properties, among others; the specific properties, however, depend on their chemistry. Since the initial report of the first MXene in 2011, the research community has primarily focused on Ti3C2Tx, and the amount of research work to investigate its synthesis and properties has increased exponentially over the years. In materials science, alloying is a useful way of synthesizing new materials to improve the properties of a class of materials. Advancement of steel and synthesis of inorganic semiconductors can be regarded as some of the major historical advancements in the concept of alloying. Thus, just one year after the initial report of MXenes, the first solid-solution MXene, (TiNb)2CTx, was reported, which demonstrates the inherent chemical tunability of this class of materials.MXenes have two sites for compositional variation: elemental substitution on both the metal (M) and carbon/nitrogen (X) sites, presenting promising routes for tailoring their properties. X-site solid-solutions include carbonitride MXenes and are the least studied class of MXenes to date. Comparatively, multi-M MXenes have acquired significant attention, leading to the extreme example of high-entropy solid-solution MXenes. By using multiple M elements, a significant expansion of the structural and chemical diversity is possible, giving rise to novel chemical, magnetic, electronic, and optical properties that cannot be accessed by single-M MXenes. Solid-solution MXenes represent the largest and most tunable class of MXenes; solid-solution MXenes are those that have multiple metals that are randomly distributed on their M sites with no distinct chemical ordering. Using multiple M elements in MXenes, it is possible to synthesize novel MXene structures that cannot be produced otherwise, such as M5X4Tx MXenes. Based on their chemistry, it is possible to rationally control the electronic, optical, mechanical, and chemical properties in a way that no other class of MXenes can. In some cases, the resultant property is linearly related to the chemistry, such as the electrical conductivity, while in other cases the properties are nonlinear or emergent: optical properties, enabling these MXenes to fulfill roles that no other MXene, or 2D material, can.In this Account, we discuss the recent progress in the synthesis, properties, applications, and outlook of solid-solution MXenes. Importantly, we demonstrate how multi-M solid-solutions can be used to tailor properties for specific applications easily.

Patternable and flexible thermoelectric generators based on Bi2Te3/silk fibroin composites for temperature sensing and wearable applications

Thermoelectric (TE) materials are functional materials that can directly convert heat energy into electrical energy, and have a positive effect on alleviating the energy crisis. Inorganic semiconductor materials have attracted extensive attention due to their excellent TE properties, among which Bi2Te3 is the best and most widely used inorganic TE material at room temperature. However, inorganic TE materials are still restricted by unfavorable factors such as scarcity of raw material resources, heavy metal pollution, high price, high rigidity, and complex processing technology, which greatly limit their development process. Therefore, it is urgent to develop flexible TE materials with high performance, non-polluting, non-toxic and low price. The combination of silk fibroin and inorganic TE materials not only retains the properties of TE materials, but also improves their flexibility. Here, the Bi2Te3/SF TE films are successfully fabricated by the evaporation-assisted self-assembly method with Seebeck coefficient of 199 μV⋅K−1 (p-type) and −240 μV⋅K−1 (n-type). In order to verify the feasibility of collecting and utilizing ambient heat energy in real life, the Bi2Te3/SF TE films are cut into various patterns (such as, flower, rabbit, tree, etc) to collect wasted ambient heat. Further, the Bi2Te3/SF thermoelectric generator (TEG) reaches a maximum power of 21 nW at a temperature difference of 43.5 K. A series of self-power temperature sensing demonstrations from single TE film, TEG, to TEG array are proposed to demonstrate their potential applications in the field of self-power sensors. Finally, by inserting Bi2Te3/SF TEG array into a bracelet, a self-powered smart bracelet can be successfully constructed, demonstrating the feasibility of the Bi2Te3/SF TE film in the development of self-powered wearable electronics.

Exploring the inorganic perovskite materials Mg3SbX3 (Where, X=I, Br, Cl and F) through the perspective of density functional theory: Adjustment of physical characteristics as consequence of strain

The solar technology industry has lately given inorganic perovskite materials an abundance of thought because of their unique optical, electrical and structural characteristics. Issues pertaining to lead (Pb) toxicity and instability require being referred to promptly, making lead-free atomically designed metal halide perovskites of foremost importance to the photovoltaic and optoelectronic industries. Perovskites, a class of inorganic metal halide semiconductors, have variant similarities with Mg3SbX3 (X = I, Br, Cl and F). According to the space group Pm-3m Mg3SbX3 (X = I, Br, Cl and F) has a cubic perovskite crystal structure. Utilizing first-principles density-functional theory (FPDFT), The intention of this investigation is to analyze how strain and spin-orbit coupling (SOC) impact the structural, electrical, optical and mechanical features of the inorganic cubic perovskite of Mg3SbX3 (X = I, Br, Cl and F). At the point between R and Γ, the Mg3SbI3,Mg3SbBr3,Mg3SbCl3 molecule displays an indirect bandgap of 0.105 eV, 0.957 eV, 1.728 eV. At the Γ point, the Mg3SbF3 molecule displays a direct bandgap of 3.184 eV. The bandgaps of the Mg3SbI3,Mg3SbBr3,Mg3SbCl3 and Mg3SbF3 perovskites are 0.198 eV, 1.203 eV, 1.901 eV and 3.723 eV respectively, when considering the spin-orbital coupling (SOC) quantum influence. A wider bandgap is investigated for increasing compressive strain while a smaller bandgap is observed for increasing tensile strain. Apart from the elastic constants and anisotropic factors, other factors that are anticipated include Pugh's ratio, Poisson's ratio, bulk modulus and others. Isotropic, ductile and mechanically stable are the words that best describe these materials, according to the elastic property evaluations. In the photon energy range that is appropriate for solar cells, the dielectric constant spikes of Mg3SbX3 are found to be visible. Therefore, Mg3SbX3 (X = I, Br, Cl and F) perovskite is a good material to use in solar cells for managing light and producing electricity.

Construction and photothermal properties of Ag nanoparticles modified multilevel porous CuO film with ultra-wide infrared spectrum absorption

Based on lattice vibration and energy band theory, narrow bandgap inorganic semiconductor materials have become a new type of photothermal material, but it is difficult to achieve absorption for long wavelength infrared radiation to meet the application requirements of ultra-wide spectrum (2.5–20 μm) infrared detectors. From the perspective of structural optics, this paper constructed a multilevel porous CuO film with both coral-like micro-porous and flower-like nano-porous structures based on chemical bath deposition technique, and the Ag nanoparticles were uniformly embedded in the "petal" gaps of flower-like nano-porous CuO by optimizing the dosages of PVP. Benefiting from the synergistic effect of multilevel porous structure and loaded Ag nanoparticles, the Ag nanoparticles modified multilevel porous CuO (CuO@Ag-PVP 0.05) film had an average absorption of 94.17 % over the wavelength range of 2.5–20 μm. The photothermal conversion efficiency of CuO@Ag-PVP 0.05 film can reach up to 81.12 % and 86.96 % over near-infrared and far-infrared light ranges, respectively. The various material characterizations and simulations analysis showed that the multilevel porous structure containing coral-like and flower-like multi-scale pores can form two guiding modes for light, and based on the synergistic effect of the two guiding modes, the CuO film can form a strong trapping effect for light over ultra-wide spectral range, broaden its absorption range, and enhance its absorption characteristics. The loaded Ag nanoparticles contain a large number of free electrons, which can capture light energy and convert it into heat energy through local surface plasmon resonance (LSPR) effect, further enhancing the light absorption and photothermal conversion efficiency.

Narrow Band Gap Base Metal Double Perovskite Oxides Through Copper Doping of Ba2Ca0.66Nb1.33O6

This work examines the influence of copper doping on the structure, optoelectronic properties, and photocatalytic performance of transition metal double perovskite oxides of the Ba2Ca0.67Nb1.33O6 (BCN) family. A solid-state synthesis method was used to achieve partial substitution of Cu2+ in the Nb5+ site (Ba2Ca0.67Nb1.33-xCuxO6-δ, x = 0.05, 0.13, 0.26) and Ca2+ site (Ba2Ca0.67-xCuxNb1.33O6-δ, x = 0.13). The incorporation of copper in BCN resulted in significant changes in the structure and optoelectronic properties. Major differences were observed when Cu atoms occupied the Nb-site versus the Ca-site. The parent compound and Ca-site doped compounds crystallized in a P3 1 space group while Nb-site doped compounds showed increasing Fm3 mixed phase character. Cu doping resulted in a dramatic shift of the absorption band edge towards the visible region. Ca-site doping resulted in a primary band edge shift from 3.8 eV to 2.1. For the Nb-site doped compounds, the primary band-edge remained at 3.8 eV but a secondary band-edge appeared which progressively shifted to smaller energies as Cu doping increased. Ba2Ca0.67Nb1.20Cu0.13O6-δ and Ba2Ca0.67Nb1.07Cu0.26O6-δ exhibited strong absorption of near-infrared photons of wavelength well beyond 800 nm. The double perovskite oxides were utilized as photoanodes for photoelectrochemical water splitting, exhibiting both a visible photoresponse (until wavelengths as low as 520 nm) and good photochemical stability. This work showcases the possibility of forming new low band gap multi-element inorganic semiconductor oxides constituted entirely of base metals and oxygen.

Regulated charge transfer by cascade dual Z-scheme heterojunction of HCdS@ZnIn2S4-Cobalt porphyrin for efficient photocatalytic solar fuel production

Dual Z-schemed photocatalysts possess superior charge-separation efficiency and powerful redox capabilities, which have attracted significant attention in photocatalytic CO2 reduction (PCR). However, most of the dual Z-scheme systems are focused on inorganic semiconductors, which remain a challenge to control the selectivity of PCR products. Herein, we designed a cascade dual Z-scheme structured organic/inorganic heterojunction of HCdS@ZnIn2S4-Cobalt porphyrin (HCdS@ZIS-CoTPPS). HCdS@ZIS-CoTPPS demonstrated excellent PCR activity (CO rate: 93.64 μmol·g−1·h−1) and adjustable syngas ratio when compared to HCdS, ZIS, CoTPPS, and HCdS/ZIS. Experimental characterizations and density functional theory (DFT) calculations reveal that the superior PCR activity of HCdS@ZIS-CoTPPS is contributed by the broad light absorption range, short charge carrier migration path, low interface contact resistance, and strong redox ability induced by the hollow structured cascade dual Z-scheme heterojunction. This article provides valuable inspiration for the design and preparation of atomistic heterojunctions for solar-driven fuel generation.

Wearable Inorganic Oxide Chemiresistor Based on Flexible Al2O3-Stabilized ZrO2 Ceramic Sponge Substrate for NO2 Sensing.

Wearable gas sensors, possessing the advantages of high sensitivity, excellent flexibility, high permeability, low weight, and workability at ambient conditions, hold great promise for real-time health monitoring and early warnings of poisonous gases. However, obtaining high-performance wearable gas sensors utilizing the current well-developed inorganic semiconductor oxide sensing materials is still very limited due to their fragile and rigid nature. Herein, a newly designed wearable gas sensor based on an all-inorganic ASZ (Al2O3-stabilized ZrO2)/ZnO/SnO2 nanofibers is introduced for the first time. The flexible ASZ ceramic sponge substrate (with a Young's modulus of 4.15 MPa) and ultrathin ZnO/SnO2 sensing layer endow the wearable gas sensor with promising properties such as super flexibility (with a bending radius of 5 mm), high gas permeability, and low weight. Furthermore, driven by UV light irradiation, this all-inorganic wearable sensor also demonstrates a stable NO2 sensing response under different bending states at room temperature, which enables the gas sensor to be more compatible with wearable sensing applications. This work offers a general method to achieve a high-performance wearable gas sensor based on inorganic materials and provides new insights into their potential in wearable gas-sensing applications.

Comparative study of atomic models of plastic deformation mechanism in ductile inorganic semiconductors: A theoretical discussion

Recently developed ductile inorganic semiconductors have opened a new avenue toward potential applications such as flexible electronics. Significant studies have been conducted based on different atomic models to understand the deformation mechanism using first-principle calculations; however, the comparative study on these atomic models remains unexplored. In this paper, taking Ag2S as an example, we simulated the slipping process using bulk, slab, and tilt-cell models. Systematic supercell tests were performed to investigate the convergence of the slip/cleavage energy based on the three atomic models. It was found that a reasonably large supercell is required to converge the slip/cleavage energy, and the ratio between minimum cleavage and maximum slip energy converges to a comparable value among different atomic models, where the tilt-cell and slab models show slightly higher energy ratio values compared with the bulk model. However, the comparison of different exchange-correlation functionals and van der Waals corrections indicates that the calculations of slip and cleavage energies are sensitive to the choice of calculation methods, highlighting the importance of using the same method for comparing slip and cleavage energies of different materials. This work provides insights into understanding different atomic models of ductility mechanisms in ductile inorganic semiconductors.

Lead-free semiconductor materials with high phase transition temperature: [1-Methylimidazole][SbBr4]

Semiconductor with structure phase change is a special multi-functional material, which plays an important role in the field of Solar Energy, information computing, sensor technology, artificial intelligence, etc. In this paper, the organic–inorganic lead-free semiconductor phase change material [1-Methylimidazole][SbBr4] (1) was successfully constructed. The IR, TGA, DSC, VT-PXRD, solid-state UV–vis spectroscopy and temperature dependence of dielectric constant were characterized and analysed. Single crystal X-ray diffraction shows that at 298 K, the space group is P21/c, the point group 2/m; an endothermic and exothermic peak appeared near 386 K and 367 K in the DSC heating–cooling cycles. Near the corresponding phase transition temperature point, compound 1 exhibits a significant reversible change in the dielectric platform. Interestingly, the band gap of compound 1 is about 2.53 eV. The existence of such interesting physical properties is closely related to the interaction between cations and anions in the molecule and the connection of internal hydrogen bonds. By constructing organic–inorganic hybrid semiconductor materials, we hope to obtain semiconductor materials with phase transition properties and actively explore and provide some ideas and support for the application of new high-tech materials.