In this study, we systematically decoupled reversible charge transitions via recombination and irreversible bulk trapping via ionization in solution-processed indium zinc oxide thin-film transistors (TFTs) under positive- and negative-bias-stress (PBS and NBS) conditions. We defined highly decoupled degradation behavior by completely evaluating time-dependent transfer characteristics and saturation leakage currents across a range of indium molarities (0.0125 M to 0.2 M). Results indicate that PBS-induced instability is likely governed by a reversible electrostatic neutralization process reducing total effective shallow and deep acceptor-like states, which are dynamically counteracted by interfacial recombination at the dielectric/semiconductor boundary. Conversely, severe degradation under NBS originated from irreversible bulk trapping triggered by the ionization of donor-like oxygen vacancies in a ZnO amorphous random network. Total effective trapped charges were calculated from threshold voltage shifts to clarify these defect kinetics quantitatively; these calculations demonstrated direct correlation with the integrated theoretical capacities of the deep and shallow acceptor-like gap-state distributions. Finally, we propose a comprehensive density of state-energy band alignment model incorporating thermal activation energies and flat-band voltages. This analytical framework proves that the composition-dependent Fermi level positioning rigorously limits and dictates complex bias-stress instabilities, offering profound insights for designing highly stable amorphous oxide semiconductor TFTs.

Ultrathin indium oxide (InOx) semiconductors are promising candidates for overcoming the performance limits of oxide electronics. In this study, the chemical and physical bulk defects in ultrathin InOx are clarified to improve the positive bias stability of chemical-solution-deposited InOx thin-film transistors (TFTs) with a yttrium oxide (YOx) capping layer (CL). By modulating channel thickness at the nanoscale, the underlying mechanisms of positive bias instability in ultrathin InOx TFTs are revealed through a combined analysis of film characteristics and computer-aided design simulation. A 2.0-nm-thick InOx channel exhibits pronounced structural disorder and retains abundant undesirable metal-hydroxide or silicon-oxygen species under the influence of the SiO2 interfacial reaction. In contrast, a 4.5-nm-thick InOx channel shows high crystallinity with comparatively low densities of oxygen-related defects. A 7.0-nm-thick InOx bulk, however, displays increased disorder and a high oxygen vacancy defect density. As a result, unlike the 2.0- and 7.0-nm-thick InOx TFTs, the 4.5-nm-thick devices exhibit a small threshold voltage shift without degradation of the subthreshold swing under strong bias stress of 6.0 MV cm−1. These findings demonstrate that nanoscale thickness optimization can simultaneously promote high crystallinity and suppress oxygen-related bulk defects, which enables TFTs with superior PBS reliability.

Flexible electronic devices that can accommodate mechanical deformations during practical use have attracted significant attention. Oxide semiconductors offer long operational lifetimes, excellent stability, and favorable electrical properties. However, sol-gel-processed oxide semiconductors are inherently brittle and typically require high-temperature annealing at > 500 °C, which limits their integration with stretchable substrates that can withstand only 120–200 °C. Consequently, a low-temperature transfer process is required for the application of oxide semiconductors in stretchable electronic devices. In this study, an indium gallium zinc oxide–ethylene glycol (IGZO–EG) solution was formulated by introducing EG into an IGZO metal precursor, enabling uniform thin-film formation and mechanically stable transfer under low-temperature conditions. The prepared films were transferred onto target substrates using a polydimethylsiloxane (PDMS)-based stamp transfer method. The surface chemistry and electrical properties of the IGZO–EG thin-film transistors (TFTs) before and after transfer were quantitatively investigated using X-ray photoelectron spectroscopy, atomic force microscopy, and electrical measurements. The results demonstrate that the PDMS-based stamp transfer process enables reliable low-temperature transfer of sol-gel-based IGZO thin films while preserving their electrical characteristics. These findings confirmed the feasibility of integrating solution-processed oxide semiconductor thin films with stretchable electronic platforms via a simple and cost-effective transfer approach.

Stretchable semiconductors capable of maintaining electrical performance under large mechanical deformation are essential for reliable wearable electronic devices. However, polymer semiconductors often suffer from electrical degradation when subjected to tensile strain. In this study, electrical stability under strain was achieved by using a rubber-blended poly(2,5-bis(2-octyldodecyl)-3,6-di(thiophen-2-yl)diketopyrrolo[3,4-c]pyrrole-1,4-dione-alt-thieno[3,2-b]thiophene) (DPPT-TT) polymer semiconductor based on a conjugated polymer/elastomer phase separation-induced elasticity (CONPHINE) structure. Unlike most previous studies on fully stretchable thin-film transistors (TFTs), which primarily report overall performance changes under mechanical strain, this work systematically identifies the dominant origin of electrical performance degradation through a stepwise electrical analysis encompassing the gate insulating layer, the semiconductor layer, and complete devices. Bottom-gate top-contact (BGTC) and bottom-gate bottom-contact (BGBC) devices were fabricated on rigid Si/SiO2 substrates to examine the intrinsic properties of the DPPT-TT/styrene-ethylene-butylene-styrene (SEBS) CONPHINE film. As a result, the device exhibits 90% mobility retention even at 100% tensile strain applied parallel to the charge transport direction. Quantitative resistance analysis using the Y-function method reveals that variations in channel resistance play a dominant role in strain-induced performance degradation, whereas changes in contact resistance contribute only marginally. These findings demonstrate that stabilizing channel resistance, rather than contact resistance, is important for achieving high mobility retention under large mechanical deformation, thereby providing concrete and quantitative design guidelines for reliable stretchable TFTs.

This study investigates the influence of post-deposition thermal annealing temperature on the crystal structure, chemical composition, and electrical performance of solution-processed indium oxide (In2O3) thin films. Based on thermogravimetric analysis (TGA) of the precursor solution, annealing temperatures of 350, 450, and 550 °C were adopted. The resulting In2O3 films were characterized using ultraviolet–visible (UV–Vis) spectroscopy, atomic force microscopy (AFM), Raman spectroscopy, and Hall-effect measurements to evaluate their optical, morphological, crystalline polymorphism, and electrical properties. The results revealed that the film annealed at 450 °C exhibited a field-effect mobility of 4.28 cm2/V·s and an on/off current ratio of 2.15 × 107. The measured hysteresis voltages were 3.11, 1.80, and 0.92 V for annealing temperatures of 350, 450, and 550 °C, respectively. Altogether, these findings indicate that an annealing temperature of 450 °C provides an optimal balance between the electrical performance and device stability for In2O3-based thin-film transistors (TFTs), making this condition favourable for high-performance oxide electronics.

This study presents a photoresist-free patterning method for solution-processed indium zinc oxide (IZO) thin films using two photochemical exposure techniques, namely pulsed ultraviolet (UV) light and UV-ozone, and a plasma-based method using oxygen (O2) plasma. Pulsed UV light delivers short, high-intensity flashes of light that induce localised photochemical reactions with minimal thermal damage, whereas UV-ozone enables smooth and uniform surface oxidation through continuous low-pressure UV irradiation combined with in situ ozone generation. By contrast, O2 plasma generates ionised oxygen species via radio frequency (RF) discharge, allowing rapid surface activation, although surface damage may occur because of energetic ion bombardment. All three approaches enabled pattern formation without the use of conventional photolithography or chemical developers, and the UV-ozone method produced the most uniform and clearly defined patterns. The patterned IZO films were applied as active layers in bottom-gate top-contact thin-film transistors, all of which exhibited functional operation, with the UV-ozone-patterned devices exhibiting the most favourable electrical performance. This comparative study demonstrates the potential of photochemical and plasma-assisted approaches as eco-friendly and scalable strategies for next-generation IZO patterning in electronic device applications.

The formation of a star-of-David charge density wave superstructure, resulting from the coordinated displacements of vanadium ions on a corner-sharing triangular lattice, has garnered significant attention to comprehend the influence of electron-phonon interaction within geometrically intricate lattice of Kagome metals, specifically AV3Sb5 (where A represents K, Rb, or Cs). However, understanding of the underlying mechanism behind charge density wave formation, coupled with symmetry-protected lattice vibrations, remains elusive. Here, from femtosecond time-resolved X-ray scattering experiments, we reveal that the phonon mode, associated with cesium ions' out-of-plane motion, becomes frustrated in the charge density wave phase. Furthermore, we observed the photoinduced emergence of a metastable charge density wave phase, facilitated by alleviating the frustration. By not only elucidating the longstanding puzzle surrounding the intervention of phonons but introducing the phononic frustration, this research offers insights into the competition between phonons and periodic lattice distortions, a phenomenon widespread in other correlated quantum materials including layered high-temperature superconductors.

Stretchable strain sensors play a pivotal role in emerging applications such as electronic skin and soft robotics, where the accurate monitoring of mechanical deformation is essential. The performance of these sensors is primarily determined by two key parameters: sensitivity and the sensing range. However, these parameters often exhibit a trade-off relationship, where enhanced sensitivity compromises the sensing range, and vice versa. In this study, we present a highly stretchable and conformal strain sensor that overcomes this limitation by integrating crack-based sensing mechanisms with a serpentine structural design. The sensor is fabricated using a simple and reproducible semiconductor-based process, comprising a gold (Au) layer thermally deposited onto a styrene-ethylene-butylene-styrene block copolymer substrate. By precise control of the deposition rate and Au film thickness, crack initiation and propagation are regulated to maximize sensitivity. The serpentine architecture not only extends the sensing range by enhancing stretchability but also ensures a uniform stress distribution across the sensor surface. The resulting device demonstrates an exceptionally high gauge factor of 321.63, a strain detection range exceeding 200%, and consistent performance over 1000 loading-unloading cycles. Furthermore, the sensor effectively detects both minute physiological signals-such as facial muscle movement and vocal cord vibration-and significant mechanical deformations, including joint articulation and plantar pressure. These results highlight the potential of the proposed sensor for applications in soft robotics, wearable electronics, and human-machine interfaces.

The recovery lifetime postponement mechanism in solution-processed (SP) indium zinc oxide (IZO) thin-film transistors (TFTs) is analytically formulated under thermal and photo-annealing conditions. A quantitative density of states (DOS) model is employed to analyse charge transport dynamics and the impact of In molarity ratios on the retention lifetime and electrical stability. The photo-retention characteristics of IZO TFTs were examined during photo-annealing, showing that higher In molarity concentrations extend the retention lifetime. To quantify this behaviour, a recovery lifetime estimation method based on post-annealing and DOS distributions is proposed. A DOS–energy diagram describing the charge transition mechanism and its relationship with the atomic structure of SP IZO semiconductors is developed. A trade-off between the prolonged retention lifetime and recovery capability with increasing In molarity is noted. This work provides a detailed framework for understanding retention lifetime dynamics, stability, and performance of SP IZO TFTs, offering insights for their widespread application in sensor devices. Transparent oxide semiconductors are important for future electronics because they combine high mobility, optical transparency, and easy processing. Indium-zinc-oxide (IZO) is a key material for flexible and transparent devices, but it faces stability issues under heat and light. Researchers studied how IZO behaves under thermal and light conditions to improve its performance. They made IZO thin-film transistors (TFTs) using a chemical process and tested them under heat and light. They found that adding more indium (In) improves conductivity but can cause permanent changes in electrical properties. The study used a model called the density of states (DOS) to understand how charges move in the material. The results show that while higher In levels increase retention time, they also make recovery harder. This research helps balance performance and stability in IZO devices. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author. Schematic illustration of retention framework for solution-processed indium zinc oxide (IZO) thin film transistors (TFTs). Indium-rich compositions generate shallow In–O related weak bonds states, leading to irreversible charge trapping and extended retention lifetime. This can be verified by the electrical charges observed after post-treatments, and the retention lifetime can be quantitatively modeled based on detailed characterization.

In this study, we explore the potential of pulsed ultraviolet (UV)-assisted thermal annealing as an effective low-temperature processing technique for fabricating high-performance indium oxide (In2O3) thin films, with a particular emphasis on their application in thin-film transistors (TFTs). In2O3 films were synthesized using a solution-based method, with indium nitrate hydrate serving as the precursor. The precursor solution was spin-coated onto SiNX/p+-Si substrates to form uniform thin films. To assess the effectiveness of the annealing approaches, we compared conventional thermal annealing at 300 degrees C with pulsed UV-assisted thermal annealing conducted at a reduced temperature of 200 degrees C. Characterization techniques- including UV-Vis spectroscopy, X-ray diffraction, atomic force microscopy, and scanning electron microscopy-revealed that pulsed UV-assisted annealing significantly improved the optical transparency, crystallinity, and carrier concentration of the films, even at lower processing temperatures. Electrical characterization of the resulting TFTs showed enhanced device performance, including higher drain currents and improved field-effect mobility, compared to devices fabricated with conventionally annealed films. Despite the improved electrical properties, the increased hydrophilicity of the UV-annealed films indicates the need for additional surface passivation to ensure long-term device stability. Overall, this work demonstrates that pulsed UV-assisted thermal annealing is a promising low-temperature processing strategy for the development of transparent oxide semiconductors in next-generation electronic devices.

Organic photodetectors (OPDs) offer considerable promise for low-power, solution-processable biosensing and imaging applications; however, their performance remains limited by spectral mismatch and interfacial trap states. In this study, a highly sensitive polymer photodiode was developed via trace incorporation (0.8 wt%) of InP/ZnSe/ZnS quantum dots (QDs) into a PTB7-Th:PC71BM bulk heterojunction (BHJ) matrix. This QD doping approach enhanced the external quantum efficiency (EQE) across the 540–660 nm range and suppressed the dark current density at −2 V by passivating interface trap states. Despite a slight decrease in optical absorption at the optimized composition, the internal quantum efficiency (IQE) increased significantly from ~80% to nearly 95% resulting in a net EQE improvement. This suggests that QD incorporation improved charge transport without compromising charge separation efficiency. As a result, the device achieved a specific detectivity (D*) of 1.8 × 1013 Jones, representing a 93% improvement over binary BHJs, along with an ultra-low dark current density of 7.76 × 10−10 A/cm2. Excessive QD loading, however, led to optical losses and increased dark current, underscoring the need for precise compositional control. Furthermore, the enhanced detectivity led to a 4 dB improvement in the signal-to-noise ratio (SNR) of photoplethysmography (PPG) signals in the target wavelength range, enabling more reliable biophotonic sensing without increased power consumption. This work demonstrates that QD-based spectral and interfacial engineering offers an effective and scalable route for advancing the performance of OPDs, with broad applicability to low-power biosensors and high-resolution polymer–QD imaging systems.

Organic ferroelectric field-effect transistors (Fe-FETs) are highly attractive for memory device applications because of their ability to read data without causing damage (nondestructive readout) and their excellent retention capabilities. These attributes make organic Fe-FETs an appealing alternative to their inorganic counterparts, which, while demonstrating superior memory performance for practical applications, still have significant challenges. This study investigates the impact of solvent selection and dielectric properties on the electrical characteristics, memory window, and long-term stability of flexible organic Fe-FETs. To this end, the electrical characteristics of devices fabricated using various organic solvents (dimethylformamide (DMF) and 2-butanone/ethyl methyl ketone (MEK)) were compared, and the results revealed that devices using polyvinylidene fluoride trifluoro ethylene (P(VDF-TrFE)) and Polyvinylidene fluoride hexafluoro-propylene (P(VDF-HFP)) in DMF exhibited higher drain currents with a larger memory window. This can be attributed to the relatively smoother surface morphology of ferroelectric films prepared with DMF. The time-dependent electrical properties of various flexible organic devices were investigated and the memory window of flexible Fe-FETs with a P(VDF-TrFE) dielectric layer exhibited excellent electrical stability. For the device with the P(VDF-HFP) dielectric, extracted memory windows (ΔVth) decreased from 25.1 to 19.0 V after two weeks. The electrical properties of P(VDF-TrFE) and P(VDF-HFP) dielectric layers exhibited entirely different tendencies depending on the solvent polarity, with the relatively simple molecular structure of the P(VDF-TrFE) film demonstrating higher electrical reliability. These results underscore the significant impact of solvent selection and the properties of the dielectric–semiconductor interface on the long-term reliability and operational efficiency of flexible Fe-FET devices.

Photomultiplication organic photodetectors (PM-OPDs) demonstrate exceptional sensitivity in low-light environments, making them valuable for imaging, environmental monitoring, and wearable health sensors. However, traditional PM-OPDs require significantly high operational voltages, which lead to elevated dark current and degraded sensitivity and noise performance. To address these limitations, a novel light-mediated PM-OPD is introduced that enhances signal gain through a cycle of light emission and reabsorption within the photoactive layers. This design integrates emission and absorption layers, achieving an external quantum efficiency exceeding 200% while maintaining a low dark current (approximate to 10-9 A cm-2) and high specific detectivity over 5.0 x 1013 Jones. By reabsorbing internally generated light to drive photomultiplication, the device enables efficient amplification without noise penalties. It achieves a 29.5 dB gain in photoplethysmography signal detection at 10 lux and demonstrates scalability for cost-effective production using thermal evaporation, making it a promising solution for low-power, high-sensitivity wearable sensors.

This study investigated the influence of solution-processed indium oxide (In2O3) thin-film transistors (TFTs) with various iodine vapor (I2) doping times. Prolonged iodine doping time is found to induce some important changes in the devices: (i) increase in In2O3 film thickness and nanoparticle size; (ii) decrease in the metal-hydroxyl bonding and increase in the metal–oxygen bonding; (iii) the positive moved threshold voltage, lower field-effect mobility, and higher on/off current ratio from 0 s (sec) to 10 s. Furthermore, vacuum thermal treatment, as a facial, novel method to recover the electrical performances of I2-doped In2O3 TFTs was examined. I2-doped In2O3 TFTs for 10 s with vacuum thermal treatment at 200 ℃ exhibited excellent recovery properties of electrical. The results indicate that iodine doping can change the electrical properties of In2O3 TFTs and could potentially be used for I2 gas sensor.

The spin-1/2 antiferromagnetic Heisenberg model on a Kagome lattice is geometrically frustrated, which is expected to promote the formation of many-body quantum entangled states. The most sought-after among these is the quantum spin liquid phase, but magnetic analogs of liquid, solid, and supersolid phases may also occur, producing fractional plateaus in the magnetization. Here, we investigate the experimental realization of these predicted phases in the Kagome material YCu3(OD)6+xBr3-x (x=0.5). By combining thermodynamic and Raman spectroscopic techniques, we provide evidence for fractionalized spinon excitations and observe the emergence of a 1/9 magnetization plateau. These observations establish YCu3(OD)6+xBr3-x as a model material for exploring the 1/9 plateau phase.

In this study, we examined the impact of crystal domain on the electrical performance and durability of flexible organic thin-film transistors (OTFTs). To analyze this, we fabricated the OTFTs on a polyimide substrate using 2,8-difluoro-5,11bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) as the organic semiconductor. To examine the influence of the film morphology and crystallinity on the electrical characteristics of OTFTs, we dissolved diF-TES-ADT in chlorobenzene and toluene solvent, annealed it at different temperatures, and then evaluated its electrical performances. The optimum annealing temperature of the diF-TES-ADT OTFTs was determined through the comprehensive analysis of the electrical parameters. The film morphology and crystallinity of organic semiconductor as a function of temperature were examined using the technical measurement analysis such as the atomic force measurement, X-ray diffraction and polarized optic microscopy. Furthermore, we demonstrated the electrical degradation of the device under prolonged bending cycles and observed the effect of bending stress on the electrical performance of OTFTs. The size of the crystalline domain and surface morphology indicated a slower deterioration of OTFT performance with an increase in the number of bending cycles. It was approved that the crystal grain size and morphology of organic semiconductor may not be critical factors determining the electrical performance of OTFTs, however, the electrical durability against bending stress was significantly degraded by these factors. We speculate that the smaller grain sizes and directionally-grown crystalline structure are highly vulnerable to bending stress, resulting in increased occurrence of void cracks and structural defects.

In this work, we report the fabrication of solution-processed bilayer-structure oxide thin-film transistors (TFTs) exhibiting superior electrical characteristics and enhanced positive/negative bias stabilities. This was achieved by tuning the carrier concentration and bandgap of the top active layer in the bilayer semiconductor. The characteristics of the top layer were modulated through aluminum (Al) doping in indium oxide semiconductors. Bilayer-channel TFTs with an optimized indium-aluminum-oxide top layer (In:Al ratio of 8:2) demonstrated effective electron transport via percolation conduction and exhibited high mobility. Furthermore, the optimized bilayer TFTs displayed small threshold voltage shifts under positive and negative bias stress, attributed to the effective formation of a quasi-two-dimensional electron gas and the suppression of oxygen vacancies. An in-depth study on engineering the carrier concentration and bandgap of the bilayer structure provides insights into material design and fabrication strategies for high-performance and stable heterostructure transistors.

We present a comprehensive investigation of the crystal and magnetic structures of the van der Waals antiferromagnet alpha- RuCl3 using single crystal x-ray and neutron diffraction. The crystal structure at room temperature is a monoclinic (C2/m). However, with decreasing temperature, a remarkable first-order structural phase transition is observed, leading to the emergence of a rhombohedral (R (3) over bar) structure characterized by three-fold rotational symmetry forming an isotropic honeycomb lattice. On further cooling, a zigzag-type antiferromagnetic order develops below T-N=6 similar to 6.6 K. The critical exponent of the magnetic order parameter was determined to be beta=0.11(1) , which is close to the two-dimensional Ising model. Additionally, the angular dependence of the magnetic critical field of the zigzag antiferromagnetic order for the polarized ferromagnetic phase reveals a six-fold rotational symmetry within the ab- plane. These findingsreflect the symmetry associated with the Ising-like bond-dependent Kitaev spin interactions and underscore the universality of the Kitaev interaction-dominated antiferromagnetic system.

Indium oxide (In2O3) thin films and thin-film transistors (TFTs) based on the solution process are prepared by pulsed UV-assisted thermal annealing at a low temperature (200 degrees C) for 5 min. The effects of pulsed UV-assisted thermal annealing on the surface morphology, chemical structure, and electrical properties of the In2O3 thin films are investigated, and they are compared with those of conventional thermal annealing (300 degrees C, 30 min). The experimental results show that the pulsed UV-assisted thermal annealing method can improve the quality of In2O3 thin film and the performance of TFT in a short period. The results of atomic force microscopy and field emission scanning electron microscopy show that the surface of the In2O3 film is denser and flatter than that of the conventional thermally annealed film, and X-ray photoelectron spectroscopy tests show that the pulsed UV-assisted thermal annealing process generates oxygen vacancies, which increases the carrier concentration and improves the electrical conductivity of the In2O3 film. In addition, the effect of pulsed UV-assisted thermal annealing on the electrical characteristics of In2O3 TFTs is investigated in a comparative way. The results show that the electrical characteristics of the device are significantly improved: the subthreshold swing decreases to 0.12 mV/dec, the threshold voltage is 7.4 V, the current switching ratio is as high as 1.29x10(7), and the field effect mobility is enhanced to 1.27 cm(2)center dot V-1 center dot s(-1). Therefore, pulsed UV-assisted thermal annealing is a simple and fast annealing method, which can rapidly improve the performances of In2O3 thin film and TFTs, even under low-temperature conditions.

In this work, based on the easy sublimation characteristics of iodine, we chose iodine vapor as the gas phase dopant. Metal oxide thin-film transistors (TFTs) are widely studied and applied due to their high mobility, high transmittance, and good stability. Based on the advantages of low temperature, low cost, and large area film formation of solution method, this preparation method has been widely used in the research of metal oxide films in recent years. However, the crystallinity of metal oxide thin films prepared by the solution method is poor and there are many internal defects, which leads to the phenomenon of high off-state current and low current switching in TFTs. Therefore, research on improving the performance of metal oxide TFTs prepared by solution method is of great significance in promoting the development of the new generation of display technology. In this study, we reported the effect of iodine doping on the electrical performance of indium zinc oxide (IZO) TFTs. To investigate the effect of iodine vapor phase doping on device performance, an IZO semiconductor layer was prepared by spin coating method on Si/SiNx substrate and TFTs were prepared using aluminum (Al) as the metal electrode. The results show that IZO TFT after iodine doping the current of the device is reduced and the field effect mobility is also reduced. With the increase in doping time threshold voltage is gradually shifted to a positive direction and the subthreshold swing is improved. The effect produced by gas phase doping of iodine on the electrical characteristics of the device reaches its maximum at a doping time of 100s. The results indicate that iodine vapor phase doping technology can improve and adjust the electrical conductivity and threshold voltage of IZO TFTs.