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This article proposes an efficient GO/CoMo3S13 chalcogel heterostructure catalyst for the hydrogen evolution reaction through the synergetic combination of the active Mo–S–Co bridge sites with shortened charge transport on graphene oxide.

Cd-based materials, despite high electron mobility and wide bandgap, are understudied for thin-film transistors. Our study explores solution-processed cadmium gallium oxide as a high-performance thin-film transistors.

Quantum dot (QD)-based optoelectronics have attracted significant interest for extensive applications due to their unique photo-functionalities such as excellent optical absorption coefficient, size-dependent bandgap tunability, and facile solution processability. However, the charge transfer correlation between surface functionalization and optoelectronic properties is still not clear. Here, we report highly photosensitive CdSe QDs/solution-processed amorphous oxide semiconductor hybrid phototransistors with highly efficient photo-induced charge carrier transport using molecular metal chalcogenide (MCC) ligands surface functionalization. Furthermore, we comprehensively investigated the photo-induced electron transfer characteristics with respect to various MCC ligands such as Sn $_{{2}}\,\,\text{S}_{{6}}^{{4-}}$ , Sn2 Se $_{{6}}^{{4-}}$ , and In2 Se $_{{4}}^{{2-}}$ . In particular, the interplay among photosensitive chelating MCC ligands of the QDs and trap-free optoelectronic performance of phototransistors was investigated. Compared to ${a}$ -IGZO thin-film transistors and oleic acid-based CdSe QDs/ ${a}$ -IGZO phototransistors, Sn $_{{2}}\,\,\text{S}_{ {6}}^{ {4-}}$ , Sn2 Se $_{ {6}}^{ {4-}}$ , and In2 Se $_{ {4}}^{ {2-}}$ -based CdSe QD/ ${a}$ -IGZO phototransistors exhibited ultrahigh photosensitivity of $8.3\times 10 ^{ {3}}$ AW−1, $3.1\times 10 ^{ {2}}$ AW−1, and $1.3\times 10 ^{ {4}}$ AW−1, respectively, in a broad range of incident light power (0.34 mW cm−2 −11.8 mW cm−2).

Molybdenum disulfide (MoS

For large-scale cathode-material synthesis, the sol-gel process with an atomically mixed metal precursor could provide a facile route to achieve a homogeneously mixed oxide-based cathode material. However, the industrial feasibility of this strategy could be limited by the high preparation cost of the precursors. Although this can be addressed by utilizing low-cost reagents and simplifying the calcination step, typically a trade-off would exist between the cost and the performance. In this study, we demonstrate the facile large-scale synthesis of lithium nickel manganese oxide (LiNi0.5Mn1.5O4) by using a polyvinylpyrrolidone-assisted citric-acid sol-gel combustion method. After single-step calcination at 900 °C for 12 h, the LiNi0.5Mn1.5O4 particles with a truncated octahedron morphology showed a superb discharge capacity (130.8 mAh·g−1) and cyclability (90.9% after 200 cycles).

Lead-free Bi–Sn alloy is an alternative solder material with a low eutectic melting temperature and environmental compatibility. Although extensive research has been conducted on this Bi–Sn eutectic alloy, a lack of facile synthetic methods with scalability hinders the implementation of finepatterned interconnectors for emerging electronic applications. In this study, we employed a facile sonochemical synthetic method to synthesize Bi–Sn alloy nanoparticles in large quantities. Highenergy ultrasonication treatment of Bi–Sn bimetallic particles resulted in nanoparticle formation with repeated formation, growth, and collapse of induced gas bubbles. The size of the nanoparticles was controlled from 92 to 506 nm of the mean diameter with variations in ultrasonication power and irradiation time. The nanoparticles exhibited a stable eutectic melting point at 139.8 °C. Interestingly, the sonochemically synthesized nanoparticles exhibited coexistence of metastable Bi2Sn and stable Bi–Sn phases. Finally, we demonstrated that Bi–Sn eutectic nanoparticles could be synthesized at a gram scale of approximately 1.7 g for future mass production.

The p-type characteristic of solution-processed metal halide perovskite transistors means that they could be used in combination with their n-type counterparts, such as indium-gallium-zinc-oxide transistors, to create complementary metal-oxide-semiconductor-like circuits. However, the performance and stability of perovskite-based transistors do not yet match their n-type counterparts, which limit their broader application. Here we report high-performance p-channel perovskite thin-film transistors based on inorganic caesium tin triiodide semiconducting layers that have moderate hole concentrations and high Hall mobilities. The perovskite channels are formed by engineering the film composition and crystallization process using a tin-fluoride-modified caesium-iodide-rich precursor with lead substitution. The optimized transistors exhibit field-effect hole mobilities of over 50 cm(2) V-1 s(-1) and on/off current ratios exceeding 10(8), as well as high operational stability and reproducibility. By optimizing the doping and crystallization behaviour of solution-processed metal halide perovskite thin films, p-channel transistors with mobilities of 50 cm(2) V-1 s(-1) and on/off ratios of 10(8) can be fabricated. Funding Agencies|Ministry of Science and ICT through the National Research Foundation - Korean government [2021R1A2C3005401, 2020R1A4A1019455, 2020M3F3A2A01085792, 2020M3D1A1110548, 2020R1A2C4001617]; Samsung Display CorporationSamsung

The significant public health concerns related to particulate matter (PM) air pollutants and the airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have led to considerable interest in high-performance air filtration membranes. Highly ferroelectric polyvinylidene fluoride (PVDF) nanofiber (NF) filter membranes are successfully fabricated via electrospinning for high-performance low-cost air filtration. Spectroscopic and ferro-/piezoelectric analyses of PVDF NF show that a thinner PVDF NF typically forms a ferroelectric β phase with a confinement effect. A 70-nm PVDF NF membrane exhibits the highest fraction of β phase (87%) and the largest polarization behavior from piezoresponse force microscopy. An ultrathin 70-nm PVDF NF membrane exhibits a high PM0.3 filtration efficiency of 97.40% with a low pressure drop of 51 Pa at an air flow of 5.3 cm/s owing to the synergetic combination of the slip effect and ferroelectric dipole interaction. Additionally, the 70-nm PVDF NF membrane shows excellent thermal and chemical stabilities with negligible filtration performance degradation (air filtration efficiency of 95.99% and 87.90% and pressure drop of 55 and 65 Pa, respectively) after 24 h of heating at 120 °C and 1 h immersion in isopropanol., Graphical Abstract ga1

Hemispherical image sensors simplify lens designs, reduce optical aberrations, and improve image resolution for compact wide-field-of-view cameras. To achieve hemispherical image sensors, organic materials are promising candidates due to the following advantages: tunability of optoelectronic/spectral response and low-temperature low-cost processes. Here, a photolithographic process is developed to prepare a hemispherical image sensor array using organic thin film photomemory transistors with a density of 308 pixels per square centimeter. This design includes only one photomemory transistor as a single active pixel, in contrast to the conventional pixel architecture, consisting of select/readout/reset transistors and a photodiode. The organic photomemory transistor, comprising light-sensitive organic semiconductor and charge-trapping dielectric, is able to achieve a linear photoresponse (light intensity range, from 1 to 50 W m

Multicomponent oxide systems are one of the essential building blocks in a broad range of electronic devices. However, due to the complex physical correlation between the cation components and their relations with the system, finding an optimal combination for desired physical and/or chemical properties requires an exhaustive experimental procedure. Here, a machine learning (ML)-based synthetic approach is proposed to explore the optimal combination conditions in a ternary cationic compound indium-zinc-tin oxide (IZTO) semiconductor exhibiting high carrier mobility. In particular, by using support vector regression algorithm with radial basis function kernel, highly accurate mobility prediction can be achieved for multicomponent IZTO semiconductor with a sufficiently small number of train datasets (15-20 data points). With a synergetic combination of solution-based synthetic route for IZTO fabrication enabling a facile control of the composition ratio and tailored ML process for multicomponent system, the prediction of high-performance IZTO thin-film transistors is possible with expected field-effect mobility as high as 13.06 cm

Color-selective multifunctional and multiplexed photodetectors have attracted considerable interest with the increasing demand for color filter-free optoelectronics which can simultaneously process multispectral signal via minimized system complexity. The low efficiency of color-filter technology and conventional laterally pixelated photodetector array structures often limit opportunities for widespread realization of high-density photodetectors. Here, low-temperature solution-processed vertically stacked full color quantum dot (QD) phototransistor arrays are developed on plastic substrates for high-resolution color-selective photosensor applications. Particularly, the three different-sized/color (RGB) QDs are vertically stacked and pixelated via direct photopatterning using a unique chelating chalcometallate ligand functioning both as solubilizing component and, after photoexposure, a semiconducting cement creating robust, insoluble, and charge-efficient QD layers localized in the a-IGZO transistor region, resulting in efficient wavelength-dependent photo-induced charge transfer. Thus, high-resolution vertically stacked full color QD photodetector arrays are successfully implemented with the density of 5500 devices cm-2 on ultrathin flexible polymeric substrates with highly photosensitive characteristics such as photoresponsivity (1.1 × 104 AW-1 ) and photodetectivity (1.1 × 1018 Jones) as well as wide dynamic ranges (>150 dB).

Electrical properties of metal oxide thin-film transistors (TFTs) are tuned via the microstructural control of organic back-channel passivation layers. In this study, organic semiconductor (OSC) passivation layers with various molecular and physicochemical properties are employed to identify the back-channel passivation mechanism in solution-processed amorphous indium gallium zinc oxide (a-IGZO) TFTs. The OSC microstructure influences the passivation of electrical defects in a-IGZO TFTs by compensating for acceptor-like trap states and dangling bonds in the back-channel. First, the distance between an n-type OSC (C60) and the a-IGZO back-channel is controlled by employing phosphonic acid molecules with different carbon chain lengths. Positive bias stress stability is tuned by applying both the OSC and carbon chain effect, leading to stable, high-performance TFTs with the determination of subgap density of states to confirm the compensation effects on the total acceptor-like defect states. The n-doping of identical passivation layers is further investigated by using perylenedicarboximide derivatives to confirm the proposed n-doping mechanism. Finally, the semiconductor 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene is selected on the basis of our proposed passivation model and exhibited good passivation characteristics. This study demonstrates an ideal molecular design for organic passivation layers, which shows significant potential for the realization of stable, high-performance TFTs.

Diacene-fused thienothiophenes (DAcTTs) have provided an excellent pi-framework for the development of high mobility p-type molecular semiconductors in the past decade. However, n-type DAcTTs are rare and their electron transport characteristics remain largely unexplored. Herein, a series of functionalized low LUMO (lowest unoccupied molecular orbital) [1]benzothieno[3,2-b][1]benzothiophene (BTBT)-based small molecules, D(C7CO)-BTBT, C7CO-BTBT-CC(CN)(2)C-7, and D(C7CC(CN)(2))-BTBT, have been developed. Detailed structural, physicochemical, optoelectronic, and single-crystal characterization were performed. The new molecules exhibit large optical band gaps (similar to 2.8-3.1 eV) and highly stabilized (-Delta E-LUMO = 1.2-1.4 eV)/pi-delocalized LUMOs as compared to p-type DAcTTs. Symmetric functionalization is found to be important to enable strong intermolecular interactions in the solid-state. All molecules exhibit alternately stacked layers of "F-BTBT-F" and "S" (F: functional group/S: substituent) with strong herringbone-like interactions (2.8-3.6 angstrom distances) between pi-cores. While carbonyls, regardless of the substituent, adopt nearly coplanar pi-backbones with BTBT, dicyanovinylenes are found to be twisted (47.5 degrees). The conformational difference at the molecular level has unusual effects on the pi-electron deficiencies, frontier molecular orbital energetics, thermal/photophysical properties, and pi-electronic structures. Dicyanovinylenes at the 2,7 positions, despite twisted conformations, are shown for the first time to yield good electron transport in DAcTTs. The D(C7CC(CN)(2))-BTBT thin film exhibits large 2D plate-like crystalline grains (similar to 1-2 mu m sizes) of terraced islands and becomes a rare example of an n-type DAcTT in organic field-effect transistors (OFETs). Although a stabilized/pi-delocalized LUMO, largely governed by functional groups and intramolecular twists, is essential for electron transport, our findings suggest that it should be combined with proper substituents to yield a favorable three-dimensional BTBT/functional group pi-electronic structure and a low intramolecular reorganization energy. Combined with our first n-type DAcTT semiconductor D(PhFCO)-BTBT, a molecular library with systematically varied chemical structures has been studied herein for the first time for low LUMO DAcTTs. The molecular engineering perspectives presented in this study may give unique insights into the design of novel electron transporting thienoacenes for unconventional optoelectronics.

Thiostannate ammonium chalcogenide aerogel (TAC) is synthesized through a unique self-crosslinking polymerization reaction between tetrahedral thiostannate dimer clusters ([Sn2S6]4−) and various ammonium ligands (NR4+). TAC is a unique and rare chalcogenide aerogel (so called “chalcogel”) stabilized without using a cationic transition metal center. In-depth and synergistic structural analyses reveal that after the self-condensation reaction, the thiostannate clusters are stabilized into a three-dimensional solid network with the support of an ammonium spacer. Consequently, thiostannate coordination is successfully transformed from tetrahedral to a distorted trigonal bipyramidal geometry, yielding a [Sn3S7]2− cluster-based porous chalcogenide network. This organic/inorganic heterostructure has a large specific surface area (158–363 m2 g−1), macroscopically random orientation of pores, soft basicity, controllable hosting ammonium ligand, and rapid mass transport through multiscale channels. These characteristics enable remarkable radionuclide control functionality such as large Cs+ adsorption capacity (141–220 mg g−1), high selectivity towards cations with intermediate chemical hardness (e.g., Cs+), structural integrity over a wide pH range (2–8), and rapid ion uptake (50% in 30 min and complete equilibrium within 3 h). This study demonstrates that the self-crosslinking mechanism of chalcometallate clusters can be utilized as a diverse platform to synthesize a broad range of chalcogenide heterostructures with desirable functionalities.

Various oxides, including Al2O3, Fe2O3, SiO2, and ZrO2, were employed as catalyst supports for the oxidation of cyclohexane by a μ-nitrido-bis[tetra(tert-butyl)phthalocyaninatoiron] complex. These oxide supports were characterized by Brunauer–Emmett–Teller surface area measurements and NH3 temperature-programmed desorption analyses. The catalyst supported on Al2O3, which has the highest acidity among the oxides considered here, showed the best activity with a turnover number (TON) of ˜108.8, without any co-catalyst. Furthermore, recycle tests of the catalysts revealed a TON of 69.3 for the Al2O3-supported catalyst after the third run. The strongly acidic sites in the Al2O3 support could be responsible for the strong adsorption of μ-nitrido diiron phthalocyanine, resulting in enhanced catalytic activity and stability.

The pursuit for a high-performance thermoelectric n-type bismuth telluride-based material is significant because n-type materials are inferior to their corresponding p-type materials in highly efficient thermoelectric modules. Herein, to improve the thermoelectric performance of an n-type Bi2Te3, we prepared Bi2Te3 nano-plates with a homogeneous sub-micron size distribution and thickness range of about a few tens of nanometers. This was achieved using a typical nano-chemical synthetic method, and the prepared materials were then spark plasma sintered to fabricate n-type nano-bulk Bi2Te3 samples. We observed a significant enhancement of the anisotropic electrical transport properties for the nano-bulk sample with a higher power factor along the in-plane direction (24.3 μW cm−1 K−2 at 300 K) than that along the out-of-plane direction (8.1 μW cm−1 K−2 at 300 K). However, thermal transport properties were insensitive along the measured direction for the nano-bulk sample. We used a dimensionless figure of merit ZT to calculate the thermoelectric performance. The results showed that the maximum ZT value of 0.69 was achieved along the in-plane direction at 440 K for the nano-bulk n-type Bi2Te3 sample, which was however smaller than that of the previously reported n-type samples (ZT of 1.1). We believe that a further enhancement of the ZT value in the fabricated nano-bulk sample could be accomplished by effectively removing the surface organic ligand of the Bi2Te3 nano-plate particles and optimizing the spark plasma sintering conditions, maintaining the nano-plate morphology intact.

Current global emergencies, such as the COVID-19 pandemic and particulate matter (PM) pollution, require urgent protective measures. Nanofibrous air filter membranes that can capture PM

Among various wearable health-monitoring electronics, electronic textiles (e-textiles) have been considered as an appropriate alternative for a convenient self-diagnosis approach. However, for the realization of the wearable e-textiles capable of detecting subtle human physiological signals, the low-sensing performances still remain as a challenge. In this study, a fiber transistor-type ultra-sensitive pressure sensor (FTPS) with a new architecture that is thread-like suspended dry-spun carbon nanotube (CNT) fiber source (S)/drain (D) electrodes is proposed as the first proof of concept for the detection of very low-pressure stimuli. As a result, the pressure sensor shows an ultra-high sensitivity of ~3050 Pa&minus, 1 and a response/recovery time of 258/114 ms in the very low-pressure range of &lt, 300 Pa as the fiber transistor was operated in the linear region (VDS = &minus, 0.1 V). Also, it was observed that the pressure-sensing characteristics are highly dependent on the contact pressure between the top CNT fiber S/D electrodes and the single-walled carbon nanotubes (SWCNTs) channel layer due to the air-gap made by the suspended S/D electrode fibers on the channel layers of fiber transistors. Furthermore, due to their remarkable sensitivity in the low-pressure range, an acoustic wave that has a very tiny pressure could be detected using the FTPS.

The successful implementation of amorphous In–Ga–Zn–O with a mobility >10 cm2 V−1 s−1 in the electronic industry indicates the significant potential of the amorphous oxide semiconductor (AOS) materials in the next-generation optoelectronics. However, the low-cost, large-area solution processes for AOS materials require high annealing temperatures (>400 °C), which is not favorable for flexible substrate application. Moreover, the lack of a doping method for AOS materials possessing an amorphous disorder structure further limits its application. In this study, a fullerene derivative (C60-malonic acid) was employed as the bulk charge-transfer dopant in solution-processed amorphous indium-zinc oxide (a-IZO) thin-film transistors. With the facile bulk charge-transfer doping from a mixed precursor solution, high-performance thin-film transistors were realized at a low annealing temperature of 250 °C. At an optimized doping concentration, the carrier mobility increased from 1.21 cm2 V−1 s−1 for an undoped a-IZO film to 2.42 cm2 V−1 s−1 for a doped a-IZO one. Furthermore, optimized doping enhanced the device stability under the bias stress condition. Therefore, the threshold voltage (Vth) shift during the positive bias stress condition (VG = 50 V; VDS = 25 V) for 1000 s drastically reduced from 28.9 V for an undoped device to 16.0 V for a device with optimized doping (1%).

Quantum dot (QD)-based optoelectronics have received great interest for versatile applications because of their excellent photosensitivity, facile solution processability, and the wide range of band gap tunability. In addition, QD-based hybrid devices, which are combined with various high-mobility semiconductors, have been actively researched to enhance the optoelectronic characteristics and maximize the zero-dimensional structural advantages, such as tunable band gap and high light absorption. However, the difficulty of highly efficient charge transfer between QDs and the semiconductors and the lack of systematic analysis for the interfaces have impeded the fidelity of this platform, resulting in complex device architectures and unsatisfactory device performance. Here, we report ultrahigh detective phototransistors with highly efficient photo-induced charge separation using a Sn

Vacancy-ordered halide double perovskites are promising non-toxic and stable alternatives for their lead-and tin (II)-based counterparts in electronic and optoelectronic applications. Despite extensive theoretical studies on this emerging family of materials, efforts devoted to the chemical modulation of their thin-film properties and their potential application in electronic devices remain rare. Here, we develop a facile one-step solution processing strategy to tune the film quality of cesium tin (IV) iodide (Cs2SnI6) perovskite and demonstrate its feasibility in thin-film transistor (TFT) application. We reveal critical roles of precursor stoichiometric ratio and solvent engineering in achieving uniform and highly crystalline Cs2SnI6 films with superior electron mobility. We further modulate the electronic properties by incorporating an external manganese (Mn2+) dopant, achieving high-performance air-stable n-channel TFTs and all-perovskite complementary inverters. We anticipate that the present study would pave the way for expanding the environmentally friendly and stable perovskites toward widespread applications. Funding Agencies|Ministry of Science and ICT through the National Research Foundation - Korean government [NRF-2021R1A2C3005401]; Samsung Display Corporation; Swedish Research Council [2020-03564]

Artificial photonic synapses are emerging as a promising implementation to emulate the human visual cognitive system by consolidating a series of processes for sensing and memorizing visual information into one system. In particular, mimicking retinal functions such as multispectral color perception and controllable nonvolatility is important for realizing artificial visual systems. However, many studies to date have focused on monochromatic-light-based photonic synapses, and thus, the emulation of color discrimination capability remains an important challenge for visual intelligence. Here, an artificial multispectral color recognition system by employing heterojunction photosynaptic transistors consisting of ratio-controllable mixed quantum dot (M-QD) photoabsorbers and metal-oxide semiconducting channels is proposed. The biological photoreceptor inspires M-QD photoabsorbers with a precisely designed red (R), green (G), and blue (B)-QD ratio, enabling full-range visible color recognition with high photo-to-electric conversion efficiency. In addition, adjustable synaptic plasticity by modulating gate bias allows multiple nonvolatile-to-volatile memory conversion, leading to chromatic control in the artificial photonic synapse. To ensure the viability of the developed proof of concept, a 7 × 7 pixelated photonic synapse array capable of performing outstanding color image recognition based on adjustable wavelength-dependent volatility conversion is demonstrated.

In this work, we report a one-step approach for synthesizing molybdenum sulfides and tungsten sulfides, using (N2H5)2MS4 (M = Mo, W) as highly energetic self-catalytic redox precursors and inducing a thermolysis process at various temperatures. These materials’ thermodynamic advantages facilitate the formation of molybdenum/tungsten sulfides at low temperatures. As expected, MoSx-100 °C (which features the [Mo3S13]2− active site model) exhibits the highest catalytic activity of the reported molybdenum sulfides. In addition, an optimized sample of crystalline WS2 was reported to produce hydrogen at 400 °C. Furthermore, the combination of carbon materials significantly enhanced the hydrogen production performance. The optimal sample of reduced graphite oxide (rGO)/MoSx-100 °C required an overpotential of only 125 mV to achieve a current density of 10 mA cm−2 and a shallow Tafel slope of 48.8 mV dec−1; this was attributed to the increased charge transfer from rGO. Furthermore, the catalyst exhibited good stability after 2000 cycles and 12 h of testing. This work may provide an alternative approach for the large-scale synthesis of transition metal dichalcogenides in high-performance catalyst applications.

The facile fabrication of an organic-inorganic hybrid nanocomposite film was investigated for a cost-effective gas barrier coating. Highly stable PAA/bentonite nanoink dispersion was achieved with high power ultrasonication treatment. The bar-coated PAA/bentonite film on PET substrate showed high barrier performance of oxygen transmission rate (OTR) value of 0.86 cc/m2·day at optimized nanoink concentration (5 wt%). In contrast, the OTR value was increased about 200 times with high ink concentraton (20 wt%). The detailed analysis of film morphology and microstructure revealed that the optimization of gas barrier properties have been achieved with proper clay platelet alignment and efficient water removal at interlayer. The gas barrier properties of one-step bar-coated barrier in this study provide industrially scalable simple gas barrier coating method for food and pharmaceutical packaging application.

Numerous LiCoO2 cathode thin-films have been prepared for all-solid-state thin-film battery applications. Preparation methods include sputtering, pulsed laser deposition, electron beam evaporation, screen printing, and spin coating. When compared to vacuum deposition methods, the solution-processed fabrication methods could result in significant cost savings and large-area production. Unfortunately, high-temperature annealing (Tanneal > 700 °C) of LiCoO2 cathode thin film is usually crucial for achieving a high performance layered phase. Here, we report on phase control of spin-coated LiCoO2 thin film by varying the molecular weight of polyvinylpyrrolidone (PVP) at low temperature. We could achieve thick and smooth film morphology by optimizing the PVP molecular weight. This method could be a promising cathode layer for low-cost thin-film batteries.

The solution processing of crystalline VO2 thin films has been intensively investigated for both fundamental studies and various electronic applications. However, previous studies have reported that the inevitable oxidation of vanadium cations in conventional precursor solutions hinders facile and reliable fabrication of VO2 thin films. Here we develop a kinetically stabilized precursor solution for solution-based VO2 thin-film fabrication. The stabilized solution precursor showed increased resistance to uncontrolled vanadium oxidation compared to conventional precursors. The synthetic conditions necessary for reliable VO2 thin-film fabrication were investigated at various oxygen concentrations and various annealing atmospheres. The oxygen level of an ambient atmosphere controls which of the three vanadium oxidation states arise, including V3 +, V4 +, and V5 + at a given temperature. The unusual occurrence of V3 + can be obtained without any reducing reagents. Nano-crystalline VO2 thin films subjected to rapid thermal shock exhibit metal-to-insulator transition at 58.9 °C and resistive switching in a metastable state at 53.5 °C, which could be further applied to future electronic devices such as memristors, Mott transistors, and Mott memories.

Correction for ‘Thiostannate coordination transformation-induced self-crosslinking chalcogenide aerogel with local coordination control and effective Cs+ remediation functionality’ by Yeo Kyung Kang et al., J. Mater. Chem. A, 2020, 8, 3468–3480, DOI: 10.1039/C9TA11282K.

Flexible organic field-effect-transistor (OFET) memory is one of the promising candidates for next-generation wearable nonvolatile data storage due to its low price, solution-processability, light-weight, mechanically flexibility, and tunable energy level via molecular tailoring. In this paper, we report flexible nonvolatile OFET memory devices fabricated with solution-processed polystyrene-brush electret and organic semiconductor blends of p-channel 6, 13-bis-(triisopropylsilylethynyl)pentacene (TIPS-PEN) and n-channel poly-{[N,N′-bis(2- octyldodecyl)-naphthalene-1,4,5,8-bis-(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)} (P-(NDI2OD-2T); N2200). Fabricated flexible OFET memory devices exhibited high memory window (30 V) and ON/OFF current ratio (memory ratio) over 103. Furthermore, we obtained reliable memory ratio (~103) over retention time of 108 s, 100 times of repeated programming/erasing cycles, and 1000 times of bending tests at a radius of 3 mm.