Enhancing the response speed of photodetectors is of great significance, for meeting the requirements of highdensity optical arrays and integration. Wide bandgap indium oxide with high electron mobility makes it suitable for the preparation of high-speed response ultraviolet photodetectors. Nevertheless, oxide semiconductor is prone to form oxygen vacancies during the growth process, leading to persistent photoconductivity in photodetectors, which considerably limits the practical application in ultraviolet detection. In this work, a wellperforming metal-semiconductor-metal structure ultraviolet photodetector based on amorphous indium-tinzinc-oxide was fabricated via co-sputtering technique. By enhancing the oxygen ratio during the co-sputtering, the concentration of oxygen vacancies was effectively reduced, which modulated the performances of the photodetector. This approach not only shortened the photodetector's response time but also omitted the annealing step, enabling a room-temperature fabrication process. As a result, the optimized indium-tin-zincoxide photodetector of 30 % oxygen exhibited remarkably rapid response characteristics under 367 nm ultraviolet irradiation, with rise and decay times of 0.018 and 0.066 s, respectively. Simultaneously, the optimized indium-tin-zinc-oxide phototransistor exhibited exceptional performance metrics, including a high photoresponsivity of 480 A/W, a detectivity of 3.2 x 1012 Jones and an external quantum efficiency of 1336 % under 367 nm ultraviolet irradiation with 1 mW/cm2 light intensity.

Photoelectrochemical (PEC) water splitting provides a scalable and integrated platform to harness renewable solar energy for green hydrogen production. The practical implementation of PEC systems hinges on addressing three critical challenges: enhancing energy conversion efficiency, ensuring long-term stability, and achieving economic viability. Metal-insulator-semiconductor (MIS) heterojunction photoelectrodes have gained significant attention over the last decade for their ability to efficiently segregate photogenerated carriers and mitigate corrosion-induced semiconductor degradation. This review discusses the structural composition and interfacial intricacies of MIS photoelectrodes tailored for PEC water splitting. The application of MIS heterostructures across various semiconductor light-absorbing layers, including traditional photovoltaic-grade semiconductors, metal oxides, and emerging materials, is presented first. Subsequently, this review elucidates the reaction mechanisms and respective merits of vacuum and non-vacuum deposition techniques in the fabrication of the insulator layers. In the context of the metal layers, this review extends beyond the conventional scope, not only by introducing metal-based cocatalysts, but also by exploring the latest advancements in molecular and single-atom catalysts integrated within MIS photoelectrodes. Furthermore, a systematic summary of carrier transfer mechanisms and interface design principles of MIS photoelectrodes is presented, which are pivotal for optimizing energy band alignment and enhancing solar-to-chemical conversion efficiency within the PEC system. Finally, this review explores innovative derivative configurations of MIS photoelectrodes, including back-illuminated MIS photoelectrodes, inverted MIS photoelectrodes, tandem MIS photoelectrodes, and monolithically integrated wireless MIS photoelectrodes. These novel architectures address the limitations of traditional MIS structures by effectively coupling different functional modules, minimizing optical and ohmic losses, and mitigating recombination losses.

Organic iontronic memristors are promising for high-density data storage, artificial synapses, and neuromorphic computing. This review provides a comprehensive summary of their concept, classification, preparation, mechanism, and application.

Due to the limitation of inherent ultra-high electron concentration, the electrical properties of In2O3 resemble those of conductors rather than semiconductors prior to special treatment. In this study, the effect of various annealing treatments on the microstructure, optical properties, and oxygen vacancies of the films and transistors is systematically investigated. Our finding reveals a progressive crystallization trend in the films with increasing annealing temperature. In addition, a higher annealing temperature is also associated with the reduction in the concentration of oxygen vacancies, as well as an elevation in both optical transmittance and optical bandgap. Furthermore, with the implementation of annealing process, the devices gradually transform from no pronounced gate control to exhibit with excellent gate control and electrical performances. The atomic layer deposited Hf-doped In2O3 thin film transistor annealed at 250 °C exhibits optimal electrical properties, with a field-effect mobility of 18.65 cm2 V−1 s−1, a subthreshold swing of 0.18 V/dec, and an Ion/Ioff ratio of 2.76 × 106. The results indicate that the impact of varying annealing temperatures can be attributed to the modulation of oxygen vacancies within the films. This work serves as a complementary study for the existing post-treatment of oxide films and provides a reliable reference for utilization of the annealing process in practical applications.

The relocation of peripheral transistors from the front-end-of-line (FEOL) to the back-end-of-line (BEOL) in fabrication processes is of significant interest, as it allows for the introduction of novel functionality in the BEOL while providing additional die area in the FEOL. Oxide semiconductor-based transistors serve as attractive candidates for BEOL. Within these categories, In2O3 material is particularly notable; nonetheless, the excessive intrinsic carrier concentration poses a limitation on its broader applicability. Herein, the deposition of Hf-doped In2O3 (IHO) films via atomic layer deposition for the first time demonstrates an effective method for tuning the intrinsic carrier concentration, where the doping concentration plays a critical role in determine the properties of IHO films and all-oxide structure transistors with Au-free process. The all-oxide transistors with In2O3: HfO2 ratio of 10:1 exhibited optimal electrical properties, including high on-current with 249 µA, field-effect mobility of 13.4 cm2 V-1 s-1, and on/off ratio exceeding 106, and also achieved excellent stability under long time positive bias stress and negative bias stress. These findings suggest that this study not only introduces a straightforward and efficient approach to improve the properties of In2O3 material and transistors, but as well paves the way for development of all-oxide transistors and their integration into BEOL technology.

Vinylene-bridged covalent organic frameworks (COFs) have shown great potential for advanced applications because of their high chemical stability and intriguing semiconducting properties. Exploring new functional monomers available for the reticulation of vinylene-bridged COFs and establishing effective reaction conditions are extremely desired for enlarging the realm of this kind of material. In this work, a series of vinylene-bridged two-dimensional (2D) COFs are synthesized by Knoevenagel condensation of tricyanomesitylene with ditopic or tritopic aromatic aldehydes. With use of appropriate secondary amines as catalysts, high-crystalline vinylene-bridged COFs were achieved, exhibiting long-range ordered structures, well-defined nanochannels, high surface areas (up to 1231 m2 g-1), and excellent photophysical properties. Under a low loading amount and short reaction time, they enable aerobic photocatalytic transformation of arylboronic acids to phenols with high efficiency and excellent recyclability. This work demonstrates a new functional monomer, tricyanomesitylene, feasible for the general synthesis of vinylene-bridged COFs with potential application in photocatalytic organic transformation, which instigates further research on such kind of material.

Establish a polymer framework coordination transition metal strategy to fabricate Co/N-PCs for energy conversion and storage.

Two-dimensional (2D) olefin-linked covalent organic frameworks (COFs) with excellent π-electron communication and high stability are emerging as promising crystalline polymeric materials. However, because of the limited species of COFs, their characteristics, processability and potential applications have not been completely understood and explored. In this work, we prepared two novel olefin-linked 2D COFs through Knoevenagel condensation of 2,4,6-trimethyl-1,3,5-triazine with tritopic triazine-cored aldehydes. The resulting COFs exhibit highly crystalline honeycomb-like structures stacked from hexagonal-latticed polymeric layers and display well-defined nanofibrillar morphologies with the uniform diameters of ca. 80 nm and ultra-lengths up to several micrometers. Such COF nanofibers can be readily composited with carbon nanotubes into high-quality continuous thin films, which are further compacted by a typical hot-pressing process to enhance their densities and mechanical strength without changing their fibrous microstructures. Such film-fabricated interdigital microelectrodes and the ionogel electrolyte are assembled into planar micro-supercapacitors (MSCs), which exhibit an outstanding areal capacitance of 44.3 mF cm-2, large operating voltage window of 2.5 V, high volumetric energy density of 38.5 mWh cm-3 as well as excellent cycling stability.

Establishing an sp2-carbon-bonding pattern is one of the efficient accesses to various organic semiconducting materials. However, the less-reversible carbon-carbon bond formation makes it still challenging to spatially construct a well-defined organic framework with π-extended two-dimensional (2D) structure through solution process. Here, a Knoevenagel condensation approach to synthesize two new 2D covalent organic frameworks (COFs) connected by unsubstituted carbon-carbon double bond linkages through activating the methyl carbons of a 2,4,6-trimethyl-1,3,5-triazine monomer is presented. The resulting sp2-carbon-linked triazine-cored 2D sheets are vertically stacked into high-crystalline honeycomb-like structures, endowing this kind of COF with extended π-delocalization, tunable energy levels, as well as high surface areas, regular open channels, and chemical stabilities. On the other hand, their microfibrillar morphologies allow for the facile manipulation of thin films as photoelectrodes without additive. Accordingly, such kinds of COF-based photoelectrodes exhibit photocurrents up to ∼45 μA cm-2 at 0.2 V vs RHE as well as rapid charge transfer rates, in comparison with imine-linked COF-based photoelectrodes. In addition, both COFs are applicable for conducting photocatalytic hydrogen generation from water splitting by visible-light irradiation.

Electrochemically driven carbon dioxide (CO2) conversion is an emerging research field due to the global warming and energy crisis. Carbon monoxide (CO) is one key product during electroreduction of CO2; however, this reduction process suffers from tardy kinetics due to low local concentration of CO2 on a catalyst's surface and low density of active sites. Herein, presented is a combination of experimental and theoretical validation of a Ni porphyrin‐based covalent triazine framework (NiPor‐CTF) with atomically dispersed NiN4 centers as an efficient electrocatalyst for CO2 reduction reaction (CO2RR). The high density and atomically distributed NiN4 centers are confirmed by aberration‐corrected high‐angle annular dark field scanning transmission electron microscopy and extended X‐ray absorption fine structure. As a result, NiPor‐CTF exhibits high selectivity toward CO2RR with a Faradaic efficiency of >90% over the range from −0.6 to −0.9 V for CO conversion and achieves a maximum Faradaic efficiency of 97% at −0.9 V with a high current density of 52.9 mA cm−2, as well as good long‐term stability. Further calculation by the density functional theory method reveals that the kinetic energy barriers decreasing for *CO2 transition to *COOH on NiN4 active sites boosts the performance.