Surface-Assisted Passivation Growth of 2D Ultrathin β-BiO Crystals for High-Performance Polarization-Sensitive Photodetectors.

2D nonlayered materials (NLMs) have garnered considerable attention due to unique surface structure and bright application prospect. However, owing to the strong interatomic forces caused by intrinsic isotropic chemical bonds in all directions, the direct synthesis of ultrathin and large area 2D NLMs remains a tremendous challenge. Here, the surface-assisted passivation growth strategy is designed to synthesize ultrathin and large size β-BiO crystals with the thickness down to 0.

Stepwise Aggregation Control of PEDOT:PSS Enabled High-Conductivity, High-Resolution Printing of Polymer Electrodes for Transparent Organic Phototransistors.

Electrohydrodynamic (EHD) jet printing is a widely employed technology to create high-resolution patterns and thus has enormous potential for circuit production. However, achieving both high conductivity and high resolution in printed polymer electrodes is a challenging task. Here, by modulating the aggregation state of the conducting polymer in the solution and solid phases, a stable and continuous jetting of PEDOT:PSS is realized, and high-conductivity electrode arrays are prepared.

Molecularly Thin 2D Organic Single Crystals: A New Platform for High-Performance Polarization-Sensitive Phototransistors.

The inherent linear dichroism (LD), high absorption, and solution processability of organic semiconductors hold immense potential to revolutionize polarized light detection. However, the disordered molecular packing inherent to polycrystalline thin films obscures their intrinsic diattenuation, resulting in diminished polarization sensitivity. In this study, we develop filter-free organic polarization-sensitive phototransistors (PSPs) with both a high linear dichroic ratio (LDR) and exceptional photosensitivity utilizing molecularly thin dithieno[3,2-b:2',3'-d]thiophene derivatives (DTT-8) two-dimensional molecular crystals (2DMCs) as the active layer.

Overcoming the Unfavorable Effects of "Boltzmann Tyranny:" Ultra-Low Subthreshold Swing in Organic Phototransistors via One-Transistor-One-Memristor Architecture.

Organic phototransistors (OPTs), as photosensitive organic field-effect transistors (OFETs), have gained significant attention due to their pivotal roles in imaging, optical communication, and night vision. However, their performance is fundamentally limited by the Boltzmann distribution of charge carriers, which constrains the average subthreshold swing (SS) to a minimum of 60 mV/decade at room temperature. In this study, an innovative one-transistor-one-memristor (1T1R) architecture is proposed to overcome the Boltzmann limit in conventional OFETs.

Impact of corporate carbon emission reduction on financing constraints.

The carbon emission reduction behaviour of enterprises is a crucial element for achieving the "double-carbon" target. Based on the panel data of China's Shanghai and Shenzhen A-share nonfinancial listed companies from 2008 to 2022, this paper explores the impact of corporate carbon emission reduction on financing constraints using the fixed effect model and further dissects the path and heterogeneity of its impact. The results show that carbon emission reduction can significantly alleviate the level of financing constraints.

Intrinsic Ferromagnetic Semiconductors with High Saturation Magnetization from Hybrid Perovskites.

Ferromagnetic semiconductors (FMS) enable simultaneous control of both charge and spin transport of charge carriers, and they have emerged as a class of highly desirable but rare materials for applications in spin field-effect transistors and quantum computing. Organic-inorganic hybrid perovskites with high compositional adjustability and structural versatility can offer unique benefits in the design of FMS but has not been fully explored. Here, a series of molecular FMSs based on the 2D organic-inorganic hybrid perovskite structure, namely (2ampy)CuCl , (3ampy)CuCl , and (4ampy)CuCl , is demonstrated, which exhibits high saturation magnetization, dramatic temperature-dependent conductivity change, and tunable ferromagnetic resonance.

Isomeric dibenzooctazethrene diradicals for high-performance air-stable organic field-effect transistors.

Realizing both high-performance and air-stability is key to advancing singlet-diradical-based semiconductors to practical applications and realizing their material potential associated with their open-shell nature. Here a concise synthetic route toward two stable dibenzooctazethrene isomers, DBOZ1 and DBOZ2, was demonstrated. In the crystalline phase, DBOZ2 exhibits two-dimensional brick wall packing with a high degree of intermolecular electronic coupling, leading to a record-breaking hole mobility of 3.

Dragon-Boat-Type Heptathienoacenes: Synthesis, Structures, and Their Applications in OFETs.

A novel synthetic strategy for efficient construction of dragon-boat-type heptathienoacenes (s) via the α-β position carbon-carbon cross-coupling between two dithienothiophenes is employed. Their crystal structures are confirmed by X-ray single-crystal analysis. The first thin film FET devices of heptathienoacenes are fabricated using OTS-treated SiO/Si substrates, in which -based devices exhibit an unprecedented highest hole mobility value of 1.

Negative Phototransistors with Ultrahigh Sensitivity and Weak-Light Detection Based on 1D/2D Molecular Crystal p-n Heterojunctions and their Application in Light Encoders.

Anomalous negative phototransistors in which the channel current decreases under light illumination hold potential to generate novel and multifunctional optoelectronic applications. Although a variety of design strategies have been developed to construct such devices, NPTs still suffer from far lower device performance compared to well-developed positive phototransistors (PPTs). In this work, a novel 1D/2D molecular crystal p-n heterojunction, in which p-type 1D molecular crystal (1DMC) arrays are embedded into n-type 2D molecular crystals (2DMCs), is developed to produce ultrasensitive NPTs.

High-yield and sustainable synthesis of quinoidal compounds assisted by keto-enol tautomerism.

The classical synthesis of quinoids, which involves Takahashi coupling and subsequent oxidation, often gives only low to medium yields. Herein, we disclose the keto-enol-tautomerism-assisted spontaneous air oxidation of the coupling products to quinoids. This allows for the synthesis of various indandione-terminated quinoids in high isolated yields (85-95%).

Bandgap Engineering of an Aryl-Fused Tetrathianaphthalene for Visible-Blind Organic Field-Effect Transistors.

Stability problem of organic semiconductors (OSCs) because of photoabsorption has become a major barrier to large scale applications in organic field-effect transistors (OFETs). It is imperative to design OSCs which are insensitive to visible and near-infrared (VNIR) light to obtain both environmental and operational stability. Herein, taking a 2,3,8,9-tetramethoxy [1,4]benzodithiino[2,3-b][1,4]benzodithiine (TTN2) as an example, we show that controlling molecular configuration is an effective strategy to tune the bandgaps of OSCs for visible-blind OFETs.

Isomeric Dibenzoheptazethrenes for Air-Stable Organic Field-Effect Transistors.

Singlet diradicaloids hold great potential as semiconductors for organic field-effect transistors (OFETs). However, their relative low material and device stabilities impede the practical applications. Here, to achieve balanced stability and performance, two isomeric dibenzoheptazethrene derivatives with singlet diradical character were synthesized in a concise manner.

Ultra-thin two-dimensional molecular crystals grown on a liquid surface for high-performance phototransistors.

A novel strategy for the growth of molecularly thin two-dimensional molecular crystals (2DMCs) of organic semiconductors with poor solubility was developed. Large-area bilayer 2DMCs were grown on a liquid surface at elevated temperatures, with record mobility and superior photoresponse.

Solution-Processed, Large-Area, Two-Dimensional Crystals of Organic Semiconductors for Field-Effect Transistors and Phototransistors.

Organic electronics with π-conjugated organic semiconductors are promising candidates for the next electronics revolution. For the conductive channel, the large-area two-dimensional (2D) crystals of organic semiconductors (2DCOS) serve as useful scaffolds for modern organic electronics, benefiting not only from long-range order and low defect density nature but also from unique charge transport characteristic and photoelectrical properties. Meanwhile, the solution process with advantages of cost-effectiveness and room temperature compatibility is the foundation of high-throughput print electrical devices.

Layer-Defining Strategy to Grow Two-Dimensional Molecular Crystals on a Liquid Surface down to the Monolayer Limit.

Two-dimensional molecular crystals (2DMCs) open a new door for the controllable growth of 2D materials by molecular design with a energy gap and solution processability. However, the growth of 2DMCs with defined molecular layers remains full of challenges. Herein, we report a novel method to produce various 2DMCs with a defined number of molecular layers.

A "Phase Separation" Molecular Design Strategy Towards Large-Area 2D Molecular Crystals.

2D molecular crystals (2DMCs) have attracted considerable attention because of their unique optoelectronic properties and potential applications. Taking advantage of the solution processability of organic semiconductors, solution self-assembly is considered an effective way to grow large-area 2DMCs. However, this route is largely blocked because a precise molecular design towards 2DMCs is missing and little is known about the relationship between 2D solution self-assembly and molecular structure.

2D Molecular Crystal Bilayer p-n Junctions: A General Route toward High-Performance and Well-Balanced Ambipolar Organic Field-Effect Transistors.

Ambipolar organic field-effect transistors (OFETs) are vital for the construction of high-performance all-organic digital circuits. The bilayer p-n junction structure, which is composed of separate layers of p- and n-type organic semiconductors, is considered a promising way to realize well-balanced ambipolar charge transport. However, this approach suffers from severely reduced mobility due to the rough interface between the polycrystalline thin films of p- and n-type organic semiconductors.

Thermal-assisted self-assembly: a self-adaptive strategy towards large-area uniaxial organic single-crystalline microribbon arrays.

Uniaxial organic single-crystalline microribbon arrays (OSCMAs) are a class of highly desirable materials for a variety of optoelectronic applications due to their favorable molecular orientations along the long axes of the ribbons. Up to now, great endeavors have been made and several solution-processing techniques have been proposed to grow uniaxial OSCMAs. However, the crystal growth parameters are tuned non-synergistically in these techniques, resulting in challenging growth condition control.

Reversible Modification of Nitrogen-Doped Graphene Based on Se-N Dynamic Covalent Bonds for Field-Effect Transistors.

Temperature-dependent modification is an effective way to reversibly tailor graphene's electronic properties. We present the reversible modification of a uniform monolayer nitrogen-doped graphene (NG) film by the formation and cleavage of temperature-dependent Se-N dynamic covalent bonds. The increasing binding energy in X-ray photoelectron spectroscopy (XPS) indicates that phenylselenyl bromine (PhSeBr) bonds with pyridinic N and pyrrolic N rather than graphitic N by accepting the lone pair of electrons.

Two-Dimensional High-Quality Monolayered Triangular WS Flakes for Field-Effect Transistors.

Large-area uniform of single-crystal tungsten disulfide (WS) is important for advanced optoelectronics based on two-dimensional (2D) atomic crystals. However, difficulties in controlling the interrelated growth parameters restrict its development in devices. Herein, we present the synthesis of triangular monolayered WS flakes with good uniformity and single crystal by adjusting the introduction time of sulfur precursor and the distances between the sources and substrates to control the nucleation density.

Sonication-assisted liquid-phase exfoliated α-GeTe: a two-dimensional material with high Fe sensitivity.

We describe sonication-assisted liquid-phase exfoliation of rhombohedral germanium telluride (α-GeTe) to obtain a good dispersion of α-GeTe nanosheets in ethanol. The thickness of the α-GeTe nanosheets is dependent on the exfoliation conditions, and few-layer α-GeTe nanosheets of 2-4 layers and even monolayer α-GeTe were obtained. We use first-principles calculations to investigate the structural, electronic, and optical properties of monolayer and bulk α-GeTe and compare the optical band gap of centrifugally fractionated α-GeTe nanosheet dispersions with the computational predictions.

Space-Confined Strategy toward Large-Area Two-Dimensional Single Crystals of Molecular Materials.

Two-dimensional molecular crystals (2DMCs) are a promising candidate for flexible and large-area electronics. Their large-area production requires both low nuclei density and 2D crystal growth mode. As an emerging type of material, their large-area production remains a case-by-case practice.

N-Type 2D Organic Single Crystals for High-Performance Organic Field-Effect Transistors and Near-Infrared Phototransistors.

Organic field-effect transistors and near-infrared (NIR) organic phototransistors (OPTs) have attracted world's attention in many fields in the past decades. In general, the sensitivity, distinguishing the signal from noise, is the key parameter to evaluate the performance of NIR OPTs, which is decided by responsivity and dark current. 2D single crystal films of organic semiconductors (2DCOS) are promising functional materials due to their long-range order in spite of only few molecular layers.

2D Organic Materials for Optoelectronic Applications.

The remarkable merits of 2D materials with atomically thin structures and optoelectronic attributes have inspired great interest in integrating 2D materials into electronics and optoelectronics. Moreover, as an emerging field in the 2D-materials family, assembly of organic nanostructures into 2D forms offers the advantages of molecular diversity, intrinsic flexibility, ease of processing, light weight, and so on, providing an exciting prospect for optoelectronic applications. Herein, the applications of organic 2D materials for optoelectronic devices are a main focus.

A bowl-shaped sumanene derivative with dense convex-concave columnar packing for high-performance organic field-effect transistors.

The charge transport properties of a bowl-shaped sumanene derivative with dense convex-concave columnar packing were studied. Single-crystal microribbons were grown by solution casting. Organic field-effect transistors based on individual single-crystal ribbons displayed a high hole mobility up to 0.