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We describe how to simulate charge diffusion in organic semiconductors using a recently introduced mixed quantum–classical method, the mapping approach to surface hopping. In contrast to standard fewest-switches surface hopping, this method propagates the classical degrees of freedom deterministically on the most populated adiabatic electronic state. This correctly preserves the equilibrium distribution of a quantum charge coupled to classical phonons, allowing one to time-average along trajectories to improve the statistical convergence of the calculation. We illustrate the method with an application to a standard model for the charge transport in the direction of maximum mobility in crystalline rubrene. Because of its consistency with the equilibrium distribution, the present method gives a time-dependent diffusion coefficient that plateaus correctly to a long-time limiting value. The resulting mobility is somewhat higher than that of the relaxation time approximation, which uses a phenomenological relaxation parameter to obtain a non-zero diffusion coefficient from a calculation with static phonon disorder. However, it is very similar to the mobility obtained from Ehrenfest dynamics, at least in the parameter regimes we have investigated here. This is somewhat surprising because Ehrenfest dynamics overheats the electronic subsystem and is, therefore, inconsistent with the equilibrium distribution. [ABSTRACT FROM AUTHOR]

Pentacene is an important model organic semiconductor in both the singlet exciton fission (SF) and organic electronics communities. We have investigated the effect of changing crystal structure on the SF process, generating multiple triplet excitons from an initial singlet exciton, and subsequent triplet recombination. Unlike for similar organic semiconductors that have strong SF sensitive to polymorphism, we find almost no quantitative difference between the kinetics of triplet pair (TT) formation in the two dominant polymorphs of pentacene. Both pairwise dimer coupling and momentum-space crystal models predict much faster TT formation from the bright singlet excited state of the Bulk vs ThinFilm polymorph, contrasting with the experiment. GW and Bethe–Salpeter equation calculations, including exciton–phonon coupling, reveal that ultrafast phonon-driven transitions in the ThinFilm polymorph compensate the intrinsically slower purely Coulomb-mediated TT formation channel, rationalizing the similarity in observed rates. Taking into account the influence of subtle structural distinctions on both the direct and phonon-mediated SF pathways reveals a predictive capability to these methods, expected to be applicable to a wide variety of molecular crystals. [ABSTRACT FROM AUTHOR]

Evaluation of the charge transport property of organic semiconductors requires exact quantum dynamics simulation of large systems. We present a numerically nearly exact approach to investigate carrier transport dynamics in organic semiconductors by extending the non-Markovian stochastic Schrödinger equation with complex frequency modes to a forward–backward scheme and by solving it using the matrix product state (MPS) approach. By utilizing the forward–backward formalism for noise generation, the bath correlation function can be effectively treated as a temperature-independent imaginary part, enabling a more accurate decomposition with fewer complex frequency modes. Using this approach, we study the carrier transport and mobility in the one-dimensional Peierls model, where the nonlocal electron–phonon interaction is taken into account. The reliability of this approach was validated by comparing carrier diffusion motion with those obtained from the hierarchical equations of motion method across various parameter regimes of the phonon bath. The efficiency was demonstrated by the modest virtual bond dimensions of MPS and the low scaling of the computational time with the system size. [ABSTRACT FROM AUTHOR]

The non-radiative energy transfer process governs the transport of excitons in organic semiconductors, directly affecting the performance of organic optoelectronic devices. Successful models describe this transfer in terms of energy donor–acceptor pair sites, in contrast to experimental photophysical properties, which reflect the average behavior of the molecular ensemble. In this study, an energetic and spatial probability density function is proposed to determine the average non-radiative energy rate for homotransfer processes. This approach considers the energetic-spatial distribution typical of disordered semiconducting polymers. The average homotransfer rate is significantly dependent on the energy of the donor site, allowing the identification of the photophysical process most likely to occur. Values of the order of 1011 s−1 were predicted and are consistent with experimental results. This approach was used to evaluate how the energy transfer efficiency in heterostructures is affected by the energy and position of the energy donor site. The model presented in this study can be explored in other organic systems to investigate exciton transport mechanisms in new organic optoelectronic device architectures. [ABSTRACT FROM AUTHOR]

This paper is dedicated to the quantum chemical package Jaguar, which is commercial software developed and distributed by Schrödinger, Inc. We discuss Jaguar's scientific features that are relevant to chemical research as well as describe those aspects of the program that are pertinent to the user interface, the organization of the computer code, and its maintenance and testing. Among the scientific topics that feature prominently in this paper are the quantum chemical methods grounded in the pseudospectral approach. A number of multistep workflows dependent on Jaguar are covered: prediction of protonation equilibria in aqueous solutions (particularly calculations of tautomeric stability and pKa), reactivity predictions based on automated transition state search, assembly of Boltzmann-averaged spectra such as vibrational and electronic circular dichroism, as well as nuclear magnetic resonance. Discussed also are quantum chemical calculations that are oriented toward materials science applications, in particular, prediction of properties of optoelectronic materials and organic semiconductors, and molecular catalyst design. The topic of treatment of conformations inevitably comes up in real world research projects and is considered as part of all the workflows mentioned above. In addition, we examine the role of machine learning methods in quantum chemical calculations performed by Jaguar, from auxiliary functions that return the approximate calculation runtime in a user interface, to prediction of actual molecular properties. The current work is second in a series of reviews of Jaguar, the first having been published more than ten years ago. Thus, this paper serves as a rare milestone on the path that is being traversed by Jaguar's development in more than thirty years of its existence. [ABSTRACT FROM AUTHOR]

Van der Waals heterostructures (vdWHs) of vertically stacked two-dimensional (2D) atomic crystals have been used to elicit intriguing phenomena stemming from strong electronic correlations, magnetic textures, and interlayer excitons spawned at the heterointerface. However, vdWHs comprised of heterointerfaces between these 2D atomic crystal lattices and molecular assemblies are emerging as equally intriguing platforms supporting properties to be harnessed for photovoltaic energy conversion, photodetection, spin-selective charge injection, and quantum emission. In this perspective, we summarize recent research examining exciton dynamics in heterostructures between semiconducting 2D transition metal dichalcogenides and molecular organic semiconductors. We discuss methods for assembly of these heterostructures, the nature of interlayer or charge-transfer excitons at transition-metal dichalcogenide (TMD)-molecule interfaces, explicit exciton transfer between organics and TMDs, and other interfacial phenomena driven by the merger of these two material classes. We also suggest key new research directions extending the remit of these 2D atomic–molecular lattice heterointerfaces into the domains of condensed matter physics, quantum sensing, and energy conversion. [ABSTRACT FROM AUTHOR]

We present an exchange–correlation approximation in which the Coulomb interaction is split into long- and short-range components and the range separation is determined by a non-empirical density functional. The functional respects important constraints, such as the homogeneous and slowly varying density limits, leads to the correct long-range potential, and eliminates one-electron self-interaction. Our approach is designed for spectroscopic purposes and closely approximates the piecewise linearity of the energy as a function of the particle number. The functional's accuracy for predicting the fundamental gap in generalized Kohn–Sham theory is demonstrated for a large number of systems, including organic semiconductors with a notoriously difficult electronic structure. [ABSTRACT FROM AUTHOR]

Dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT) is a widely used small-molecular p-type organic semiconductor. Despite the broad availability of high-performance DNTT transistors, there is a lack of investigation into other devices based on this semiconductor. In this study, rectifying diodes with DNTT as a single transport medium are fabricated and characterized. Realizing unipolar current rectification from asymmetric metal contacts, a number of physical and electrical properties of DNTT are made accessible. Current–voltage measurement, broad-band impedance spectroscopy, drift-diffusion simulation, and equivalent-circuit modeling are combined to quantify important parameters such as dielectric constant, trap energy, and lifetime. These results provide a practical reference for the design and optimization of diverse electronic devices incorporating DNTT. [ABSTRACT FROM AUTHOR]

Pentacene is one of the most investigated organic semiconductors. It is well known that the motion of excitons in pentacene and other organic semiconductors is determined by inter-molecular exciton coupling based on charge-transfer processes. In the present study, we demonstrate the impact of the admixture of tetracene, which has a larger band gap and interrupts the pentacene–pentacene interaction, on the exciton behavior in pentacene. Using a combination of optical absorption and electron energy-loss spectroscopy, we show that both the Davydov splitting and the exciton band width in pentacene strongly decrease with increasing tetracene concentration, while the decrease of the exciton band width is substantially larger. [ABSTRACT FROM AUTHOR]

Graph neural networks (GNNs) have demonstrated promising performance across various chemistry-related tasks. However, conventional graphs only model the pairwise connectivity in molecules, failing to adequately represent higher order connections, such as multi-center bonds and conjugated structures. To tackle this challenge, we introduce molecular hypergraphs and propose Molecular Hypergraph Neural Networks (MHNNs) to predict the optoelectronic properties of organic semiconductors, where hyperedges represent conjugated structures. A general algorithm is designed for irregular high-order connections, which can efficiently operate on molecular hypergraphs with hyperedges of various orders. The results show that MHNN outperforms all baseline models on most tasks of organic photovoltaic, OCELOT chromophore v1, and PCQM4Mv2 datasets. Notably, MHNN achieves this without any 3D geometric information, surpassing the baseline model that utilizes atom positions. Moreover, MHNN achieves better performance than pretrained GNNs under limited training data, underscoring its excellent data efficiency. This work provides a new strategy for more general molecular representations and property prediction tasks related to high-order connections. [ABSTRACT FROM AUTHOR]

The addition of molecular dopants into organic semiconductors (OSCs) is a ubiquitous augmentation strategy to enhance the electrical conductivity of OSCs. Although the importance of optimizing OSC–dopant interactions is well-recognized, chemically generalizable structure–function relationships are difficult to extract due to the sensitivity and dependence of doping efficiency on chemistry, processing conditions, and morphology. Computational modeling for an integrated OSC–dopant design is an attractive approach to systematically isolate fundamental relationships, but requires the challenging simultaneous treatment of molecular reactivity and morphology evolution. We present the first computational study to couple molecular reactivity with morphology evolution in a molecularly doped OSC. Reactive Monte Carlo is employed to examine the evolution of OSC–dopant morphologies and doping efficiency with respect to dielectric, the thermodynamic driving for the doping reaction, and dopant aggregation. We observe that for well-mixed systems with experimentally relevant dielectric constants, doping efficiency is near unity with a very weak dependence on the ionization potential and electron affinity of OSC and dopant, respectively. At experimental dielectric constants, reaction-induced aggregation is observed, corresponding to the well-known insolubility of solution-doped materials. Simulations are qualitatively consistent with a number of experimental studies showing a decrease of doping efficiency with increasing dopant concentration. Finally, we observe that the aggregation of dopants lowers doping efficiency and thus presents a rational design strategy for maximizing doping efficiency in molecularly doped OSCs. This work represents an important first step toward the systematic integration of molecular reactivity and morphology evolution into the characterization of multi-scale structure–function relationships in molecularly doped OSCs. [ABSTRACT FROM AUTHOR]

The design principles of acceptor1–acceptor2 copolymers featuring alternating diketopyrrolopyrrole (DPP) and thienopyrrolodione (TPD) moieties are investigated. The investigated series of polymers is obtained by varying the aromatic linker between the two acceptor motifs between thiophene, thiazole, pyridine, and benzene. High electron affinities between 3.96 and 4.42 eV, facilitated by the synergy of the acceptor motifs are determined with optical gaps between 1.37 and 2.02 eV. Grazing incidence wide-angle X-ray scattering studies reveal a range of film morphologies after thermal annealing, including face-on, end-on and superstructure edge-on-like crystallites. Conversely, all materials form thin edge-on layers on the polymer–air interface, as demonstrated by multi-elemental near-edge X-ray absorption fine-structure spectroscopy. The benefit of the electron-deficient linkers thiazole and pyridine is evident: In organic field effect transistors, electron mobilities of up to 4.6 × 10−2 cm2 V−1 s−1 are obtained with outstanding on/off current ratios of 5 × 105, facilitated by the absence of detectable hole transport in these materials. Viability for all-polymer solar cells is assessed in active layer blends with the donor polymer PM6, yielding a maximum average power conversion efficiency of 4.8% and an open circuit voltage above 1 V.

The semiconductor/insulator blends for organic field-effect transistors are a potential solution to improve the charge transport in the active layer by inducing phase separation in the blends. However, the technique is less investigated for long-chain conducting polymers such as Poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno [3,2-b]thiophene)] (DPPDTT), and lateral phase separation is generally reported due to the instability during solvent evaporation, which results in degraded device performance. Herein, we report how to tailor the dominant mechanism of phase separation in such blends and the molecular assembly of the polymer. For DPPDTT/PMMA blends, we found that for higher DPPDTT concentrations (more than 75%) where the vertical phase separation mechanism is dominant, PMMA assisted in the self-assembly of DPPDTT to form nanowires and micro-transport channels on top of PMMA. The formation of nanowires yielded 13 times higher mobility as compared to pristine devices. For blend ratios with DPPDTT ≤ 50%, both the competing mechanisms, vertical and lateral phase separation, are taking place. It resulted in somewhat lower charge carrier mobilities. Hence, our results show that by systematic tuning of the blend ratio, PMMA can act as an excellent binding material in long-chain polymers such as DPPDTT and produce vertically stratified and aligned structures to ensure high mobility devices. [ABSTRACT FROM AUTHOR]

Physical vapor deposition (PVD) provides a route to prepare highly stable and anisotropic organic glasses that are utilized in multi-layer structures such as organic light-emitting devices. While previous work has demonstrated that anisotropic glasses with uniaxial symmetry can be prepared by PVD, here, we prepare biaxially aligned glasses in which molecular orientation has a preferred in-plane direction. With the collective effect of the surface equilibration mechanism and template growth on an aligned substrate, macroscopic biaxial alignment is achieved in depositions as much as 180 K below the clearing point TLC−iso (and 50 K below the glass transition temperature Tg) with single-component disk-like (phenanthroperylene ester) and rod-like (itraconazole) mesogens. The preparation of biaxially aligned organic semiconductors adds a new dimension of structural control for vapor-deposited glasses and may enable polarized emission and in-plane control of charge mobility. [ABSTRACT FROM AUTHOR]

When an impurity with a light mass is inserted into a crystal, it can undergo a high-frequency oscillation referred to as a local vibrational mode (LVM). A Fermi resonance may occur between the LVM and lower-frequency modes of the defect. The LVM may also interact with phonons or the electromagnetic field. Understanding these interactions can help model and control diffusion, defect reactions, and thermal conductivity. LVMs have been probed in semiconductors using pressure and alloying as experimental parameters, resulting in anticrossing between localized and extended vibrational modes. These types of vibrational interactions could play an important role in the stability and thermal properties of organic–inorganic hybrid semiconductors. The coupling between an LVM and electromagnetic wave yields an "LVM polariton," an excitation that has significant vibrational and electric-field amplitudes. [ABSTRACT FROM AUTHOR]

Periodic density functional theory was employed to investigate the impact of chemical modifications on the properties of π-conjugated acenedithiophene molecular crystals. Here, we highlight the importance of the β-methylthionation effect, the position of the sulfur atoms of the thiacycle group and their size, and the number of central benzene rings in the chemical modification strategy. Our results show that the introduction of the methylthio groups at the β-positions of the thiophene and the additional benzene ring at the center of the BDT crystal structure are a promising strategy to improve the performance of organic semiconductors, as observed experimentally. We found that β-MT-ADT exhibits large charge carrier mobility, which is in good agreement with the experimental results and comparable to that of rubrene. In addition, the electronic and optical properties of these ambipolar materials suggest promising performances with β-MT-ADT > ADT > β -MT-NDT > NDT > BEDT-BDT > β -MT-BDT > BDT. Moreover, functionalization with thiacycle-fused sulfur atoms of different sizes and numbers improve the properties of BDT but is still less efficient than the methylthionation effect. Overall, our findings suggest a promising molecular modification strategy for possibly high performance ambipolar organic semiconducting materials. [ABSTRACT FROM AUTHOR]

Designing organic semiconductors for practical applications in organic solar cells, organic field-effect transistors, and organic light-emitting diodes requires understanding charge transfer mechanisms across different length and time scales. The underlying electron transfer mechanisms can be efficiently explored using semiempirical quantum mechanical (SQM) methods. The dimer projection (DIPRO) method combined with the recently introduced non-self-consistent density matrix tight-binding potential (PTB) [Grimme et al., J. Chem. Phys. 158, 124111 (2023)] is used in this study to evaluate charge transfer integrals important for understanding charge transport mechanisms. PTB, parameterized for the entire Periodic Table up to Z = 86, incorporates approximate non-local exchange, allowing for efficient and accurate calculations for large hetero-organic compounds. Benchmarking against established databases, such as Blumberger's HAB sets, or our newly introduced JAB69 set and comparing with high-level reference data from ωB97X-D4 calculations confirm that DIPRO@PTB consistently performs well among the tested SQM approaches for calculating coupling integrals. DIPRO@PTB yields reasonably accurate results at low computational cost, making it suitable for screening purposes and applications to large systems, such as metal-organic frameworks and cyanine-based molecular aggregates further discussed in this work. [ABSTRACT FROM AUTHOR]

Chiral materials exhibit many interesting physical properties including circular dichroism, circularly polarized photoluminescence, and spin selectivity. Since its discovery, chirality-induced spin selectivity (CISS) has been demonstrated in many chiral material systems, which indicates promising applications in spintronic devices. Thus, searching for compounds that possess both sizable chirality and excellent spin transport properties is in order. Hybrid organic–inorganic perovskites have attracted intensive research interest due to their long carrier lifetime, high carrier mobility, chemically tunable electronic properties, and long spin lifetime, which make this emerging class of semiconductors promising candidate for spintronics. Moreover, hybrid perovskites integrate inorganic octahedral framework and organic ligands, which may introduce chirality into the materials, especially in quasi-two-dimensional structures. Recently, CISS has been observed in 2D chiral hybrid perovskites, showing the spin filtering effect. Studies of CISS in chiral hybrid perovskites not only help deepen our understanding of CISS mechanism but also shed new light on designing novel spintronic devices. In this review, we summarize the state-of-the-art studies of CISS effect in 2D chiral hybrid organic–inorganic perovskites system. We also discuss the remaining challenges and research opportunities of employing CISS in next-generation spintronic devices. [ABSTRACT FROM AUTHOR]

The current investigation focuses on the development of capacitive humidity sensors utilizing an organic polymer blend of poly[4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)benzo[1,2-b;4,5-b′]dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] (PTB7-Th) and [6,6]-phenyl-C71-butyric-acid methyl ester (PC71BM), which were successfully achieved. A cost-effective spin-coating technique was employed to produce surface-type sensors in the Al/PTB7-Th:PC71BM/Al horizontal geometry. The investigation focuses on the capacitive behavior of the devices under ambient conditions, specifically at room temperature. The devices are subjected to an alternating current operational bias of 1 V, while the relative humidity (RH) is varied within the range of 20–95%. The sensors are examined at frequencies of 100 Hz, 1 kHz, 10 kHz, and 100 kHz. Specifically, the sensors demonstrate improved sensitivity to changes in capacitance in relation to relative humidity when operating at a frequency of 100 Hz. In addition, an optimal volumetric ratio of 1.5:1 is selected for PTB7-Th to PC71BM. The optimized composite sensor demonstrates superior performance, exhibiting minimal hysteresis of 6.16% and significant sensitivity of 1.58 pF/% RH. In addition, response and recovery times of 2 s and 3 s, respectively, are obtained. The results of investigations demonstrate that the composite sensor exhibits significant improvements in sensing parameters compared to single-material sensors. As a result, the composite sensor has great potential for use in advanced sensor applications, especially in the education sector in underdeveloped countries. [ABSTRACT FROM AUTHOR]

This review article presents insights into acoustic interactions with semiconductors, exploring a continuum from electron dynamics to exciton behavior while highlighting recent developments in organic material systems. Various aspects of acoustic interactions, encompassing the manipulation of electrons and their transport mechanisms for applications in the fields of acoustoelectric and acousto-optics, explored by studying surface acoustic wave (SAW) devices integrated with inorganic and organic semiconductors, are presented here. SAWs are guided waves propagating along a piezoelectric material surface, inducing acoustic strain and piezoelectric fields within a semiconductor upon contact. These fields create a dragging force, transferring energy and momentum into the semiconductor, which manipulate and transport charge carriers, thereby generating an acoustoelectric current. Furthermore, SAW can influence exciton dynamics via type-II as well as type-I band-edge modulations, leading to alterations in their spatial distribution, causing transport of electron–hole pairs as distinct charge carrier packets and as bound pairs, respectively, along the SAW path. This paper explores advancements in these phenomena, shedding light on innovative applications and, especially, novel insights into the dynamic interplay between acoustics and organic semiconductor physics. The review concludes by outlining challenges and prospects in the field of SAW and semiconductor interactions, providing a roadmap for future research endeavors. [ABSTRACT FROM AUTHOR]

Determining the electronic levels associated with polarons, the fundamental charge carriers in organic semiconductors, is key to understanding the charge transport properties of these materials. Recent findings challenge the traditional view of these electronic levels by highlighting the importance of intra‐molecular Coulomb interactions in polarons. Experimental evidence was previously presented for a revised model of the negative polaron in the case of the polymer semiconductor poly(NDI2OD‐T2); there, the addition of an excess electron was seen to lead to the emergence of a singly occupied state within the energy gap of the undoped material and an unoccupied state above the edge of the conduction states. Here, focus is on a small‐molecule semiconductor, C60, and spectral evidence is provided of a similar picture for the new states appearing upon polaron formation. Specifically, direct and inverse photoemission spectroscopy is used to investigate the density of states in C60 films n‐doped with two dimeric dopants. The Coulomb interaction energy (Hubbard U) of the C60 anion is experimentally determined to be ≈1.1 eV, a value that aligns closely with theoretical predictions. [ABSTRACT FROM AUTHOR]

Rapid, nondestructive characterization techniques for evaluating the degree of crystallinity and phase segregation of organic semiconductor blend thin films are highly desired for in‐line, automated optoelectronic device fabrication facilities. Here, it is demonstrated that reflection polarized optical microscopy (POM), a simple technique capable of imaging local anisotropy of materials, is capable of determining the relative degree of crystallinity and phase segregation of thin films of polymer:fullerene blends. While previous works on POM of organic semiconductors have largely employed the transmission geometry, it is demonstrated that reflection POM provides 3× greater contrast. The optimal configuration is described to maximize contrast from POM images of polymer:fullerene films, which requires Köhler illumination and slightly uncrossed polarizers, with an uncrossing angle of ±3°. It is quantitatively demonstrated that contrast in POM images directly correlates with 1) the degree of polymer crystallinity and 2) the degree of phase segregation between polymer and fullerene domains. The origin of the bright and dark domains in POM is identified as arising from symmetry‐broken liquid crystalline phases (i.e., dark conglomerates), and it is proven that they have no correlation with surface topography. The use of reflection POM as a rapid diagnostic tool for automated device fabrication facilities is discussed. [ABSTRACT FROM AUTHOR]

Despite major advances in efficiency, the operational stability of organic photovoltaic (OPV) devices remains poor. Therefore, understanding the degradation mechanisms and identifying potential solutions to improve device stability is critical to enabling the widespread commercialization of OPVs. Herein, simple filtration of the PBDB‐T:ITIC photoactive layer (PAL) solution prior to film deposition is demonstrated to enhance OPV device operational stability without compromising initial device performance. The effect of filtration, a commonly used but poorly understood OPV fabrication step, is investigated using a range of chemical, structural, and optoelectronic methods, on solutions and films. Filtration is found to remove large aggregates from solution without disrupting nanoscale preaggregation, resulting in enhanced acceptor ordering in PBDB‐T:ITIC thin films, significantly improving morphological stability and photostability. This simple and facile method is confirmed to be a general strategy that also works for other PBDB‐T‐containing OPV blends, including Y6‐based systems, and highlights how subtle changes in morphology can result in dramatic differences in operational stability. [ABSTRACT FROM AUTHOR]

In the context of human active response to exponentially increasing data volumes, memristors have emerged as a focal point in systematic problem‐solving approaches. Particularly, organic memristors, characterized by excellent scalability, flexibility, and 3D stacking capabilities, have shown its tremendous potential in innovative electronic applications. However, the modulation of molecular assembly and interface interaction at the electrode surface poses a challenging task, despite their crucial role in determining the memristive performance. Herein, a collaborative method involving hydrophobic molecular design and interface engineering is proposed to generate high‐quality nanofilms with optimal photoelectric and electrochemical properties. By subjecting the bottom electrode to O2 plasma treatment and chemical modification using a hydrophobic ionic liquid poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide (PTFSI), the hydrophobic compound DN demonstrates exceptional affinity and stronger intermolecular interactions with the electrode surface. Consequently, the two‐terminal device array comprising Al/DN@PTFSI/ITO exhibits robust non‐volatile write‐once‐read‐many times (WORM) memory behavior, resulting in a tripling production yield from 30% to 92% along with a lower threshold voltage of 1.5 V, higher ON/OFF current ratio of 103 and excellent stability. This study presents a versatile approach to optimize the film assembly and material/electrode interface, thereby accelerating the development of organic memristors toward future applications. [ABSTRACT FROM AUTHOR]

For the prosthetic retina, a device replacing dysfunctional cones and rods, with the ability to mimic the spectral response properties of these photoreceptors and provide electrical stimulation signals to activate residual visual pathways, can relay sufficient data to the brain for interpretation as color vision. Organic semiconductors including conjugated polymers with four different bandgaps providing wavelength‐specific electrical responses are ideal candidates for potential full‐color vision restoration. Here, conjugated polymer photocapacitor devices immersed in electrolyte are demonstrated to elicit a photovoltage measured by a Ag/AgCl electrode 100 microns from the device of ≈−40 mV for 15–39 µW mm−2 of incident light power density at three wavelengths: 405 nm for blue photoreceptor candidate material, 534 nm for green, 634 nm for red. Photoresponse is substantially improved by introducing polymer donor/acceptor molecules bulk heterojunctions. Devices with bulk heterojunction configurations achieved at least −70 mV for green candidates with the highest at −200 mV for red cone candidates. These findings highlight the potential for organic materials to bridge the gap toward natural vision restoration for retinal dystrophic conditions such as age‐related macular degeneration, Stargardt disease, or retinitis pigmentosa and contribute to the ongoing advancements in visual prosthetic devices. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) attract significant attention due to their ordered, crystalline, porous, metal‐free, and predictable structures. These unique characteristics offer great opportunities for the diffusion and transmission of photogenerated charges during photocatalysis. Currently, a considerable number of COFs are used as metal‐free organic semiconductor photocatalysts. This review aims to understand the relationships between the structure and photocatalysis performance of COFs and provides in‐depth insight into the synthetic strategy to improve photocatalysis performance. Subsequently, the review focuses on the structural motif of COFs in sustainable photocatalytic hydrogen evolution, carbon dioxide reduction, hydrogen peroxide generation, and organic compound transformations. Last, in conjunction with the significant progress achieved and the challenges yet to be overcome, a candid discussion is undertaken regarding the challenges and opportunities in the field of COF photocatalysis, accompanied by the presentation of potential research avenues and future directions. This review seeks to provide readers with a comprehensive understanding of the pivotal role of COFs in the field of photocatalysis, to offer robust guidance for the innovative utilization of COFs in future sustainable photocatalysis. [ABSTRACT FROM AUTHOR]

Exciton binding energy (Eb) is understood as the energy required to dissociate an exciton in free‐charge carriers, and is known to be an important parameter in determining the performance of organic opto‐electronic devices. However, the development of a molecular design to achieve a small level of Eb in the solid state continues to lag behind. Here, to investigate the relationship between aggregation and Eb, star‐shaped π‐conjugated compounds DBC‐RD and TPE‐RD were developed using dibenzo[g,p]chrysene (DBC) and tetraphenylethylene (TPE). Theoretical calculations and physical measurements in solution showed no apparent differences between DBC‐RD and TPE‐RD, indicating that these molecules possess similar properties on a single‐molecule level. By contrast, pristine films incorporating these molecules showed significantly different levels of electron affinity, ionization potential, and optical gap. Also, DBC‐RD had a smaller Eb value of 0.24 eV compared with that of TPE‐RD (0.42 eV). However, these molecules showed similar Eb values under dispersed conditions, which suggested that the decreased Eb of DBC‐RD in pristine film is induced by molecular aggregation. By comparison with TPE‐RD, DBC‐RD showed superior performances in single‐component organic solar cells and organic photocatalysts. These results indicate that a molecular design suitable for aggregation is important to decrease the Eb in films. [ABSTRACT FROM AUTHOR]

Silver nanowires-embedded polydimethylsiloxane (AgNWs/PDMS) electrodes are promising components for various soft electronics, but face energy mismatch with organic semiconductors. Attempts at galvanic replacement, involving spontaneous gold (Au) formation on the electrodes, often result in non-uniform and particulate Au coatings, compromising device performance and stability. In this study, we introduce a novel approach for achieving a uniform and complete Au coating on AgNWs/PDMS electrodes by adding NaCl to the Au complex solution. This addition slows down the galvanic replacement process and prevents precipitation, enabling a uniform and complete Au coating on the AgNWs surface. Such coating significantly reduces contact resistance (RC), thereby enhancing the electrical characteristics of p-type organic transistors. Furthermore, the development of high-performance, fully soft organic transistors was achieved incorporating an organic semiconductor-elastomer blend. Additionally, reliable, mechanically stable soft glucose sensor was developed, taking advantage of the complete Au coating, which protects against oxidation during the glucose sensing process. [ABSTRACT FROM AUTHOR]

Photovoltaic is one of the best low-cost alternative energy sources. In this paper, organic semiconductors were explored as light harvesters due to their extraordinary properties, but initially, the scientific community focused on synthesizing the large bandgap organic semiconductors, which were unsuitable for photovoltaic applications. Wide bandgap organic semiconductors can capture light only from the UV–Vis region of the solar spectrum, thus showing solar cells' power conversion efficiency (PCE) of less than 5%. By reducing the bandgap, organic semiconductors can show good compatibility with the air mass (AM) of 1.5 solar spectrums. So, the attention came toward synthesizing low bandgap semiconductors, which led to the enhancement of PCE from 5% to 17%. This review summarizes the overall development of the last 15 years in the field of organic photovoltaic semiconductors. The significant parameters in organic semiconductors are their bandgap, the position of the highest occupied molecular orbital (HOMO), and the lowest unoccupied molecular orbital (LUMO) that can easily be tuned chemically by molecular designing. One of the issues in organic photovoltaic solar devices is the need for absorbers with a narrow bandgap to maximize power conversion efficiencies to a great extent. Moreover, several factors, such as conjugation length, bond length alteration, intermolecular interaction, donor–acceptor charge transfer, planarity, and physical states, are responsible for tuning the bandgap. This review also classifies low bandgap semiconductors based on the core skeleton with their bandgaps, structures, and power conversion efficiencies. [ABSTRACT FROM AUTHOR]

Thin-film devices that transduce the chemical activity of ions into electronic signals are essential components in various applications, including healthcare diagnostics and environmental monitoring. Combinations of organic semiconductors (OSCs) and ionselective materials have been explored for developing solution-processable ion sensors. However, the necessity of reference electrodes (REs) and operational stability in ionpermeable OSCs have posed questions regarding whether reliable measurements with thin-film components are attainable with OSCs. Herein, we report electric double-layer transistors (EDLTs) with OSCs in single-crystal forms for ion sensing. Our EDLTs demonstrated high operational stability, with a one-to-one relationship between the source electrode potential and device resistance, and served as quasi-REs (qRE). When our EDLT is served as qRE, its drift was as small as 0.5 mV/h and comparable to that of commonly employed REs. In our system, the semiconductor-electrolyte interface is self-passivated by the alkyl chains of OSCs in single-crystal structures, with the two-dimensional transport layer appearing unaltered upon gating. EDLT arrays with ion-selective and nonselective liquid junctions enable ion concentration sensing without a conventional RE. These findings provide opportunities to develop thin-film devices based on OSCs for easy integration and reliable measurements. [ABSTRACT FROM AUTHOR]

Organic semiconductors are used in organic opto‐electronic devices because of their various advantages. However, they are vulnerable to moisture and oxygen. Thus, flexible and transparent encapsulations with barrier properties against moisture and oxygen need to be developed to fabricate bendable and foldable organic semiconductor devices. In this study, a simple and highly productive self‐assembly process is developed from montmorillonites by using maximized Marangoni forces and a co‐solvent in an aqueous water and a non‐aqueous N‐methyl‐2‐pyrrolidone medium for the fabrication of a flexible and transparent encapsulation film. Water vapor transmission rate (WVTR) and optical transmittance of montmorillonite‐based flexible and transparent encapsulation films are modulated using different precursor solution concentrations and numbers of stacked montmorillonite layers. Long‐term stability of transparent polymer solar cells with self‐assembled flexible and transparent encapsulation films (WVTR of 6.66 × 10−3 g m−2 day−1 and optical transmittance of 90.5% at 550 nm) is enhanced, and performance of flexible polymer light‐emitting diodes with flexible encapsulation films is maintained after 1000 bending cycles, even at a bending radius of 2 mm. Mechanical properties of prepared encapsulation films are analyzed by conducting tensile tests and finite element analysis simulations, demonstrating that an integrated analysis includes both devices and encapsulation films. [ABSTRACT FROM AUTHOR]

N‐type organic semiconductors are essential for the advancement of organic electronic devices. However, in relation to extensive research on n‐type and p‐type polymers, studies on high‐mobility n‐type small‐molecule semiconductors (SMSCs) are limited. Here, a series of ultra‐narrow bandgap n‐type SMSCs are developed on an A‐D‐A‐type structure. These SMSCs feature an exceptionally large π‐conjugated area, leading to strong intramolecular charge transfer and robust π‐π interactions. For the first time, central core and terminal halogenation are employed to control molecular surface electrostatic potential distribution, thereby regulating the π‐π stacking area (Sπ‐π) and studying their correlation. The research reveals that, in n‐type SMSCs with an edge‐on arrangement, introducing fluorine into the 2D central core can reduce the Sπ‐π, which is detrimental to the electron mobility (µe) of organic field‐effect transistors (OFETs). Conversely, terminal chlorination facilitates electron injection and improves µe. Consequently, DTPC‐OD‐4Cl, featuring shorter alkyl side chains and a non‐fluorinated 2D central core and undergoing terminal chlorination, achieved the highest µe of up to 0.52 cm2 V−1 s−1, ranking among the highest values reported for A‐D‐A type SMSCs. This work not only systematically investigated the influence of molecular structure on mobility but also provided novel insights for designing more efficient n‐type SMSCs. [ABSTRACT FROM AUTHOR]

Achieving high electrical conductivity (σ) and power factor (PF) simultaneously remains a significant challenge for n‐type organic themoelectrics (OTEs). Herein, we demonstrate the state‐of‐the‐art OTEs performance through blending a fused bithiophene imide dimer‐based polymer f‐BTI2g‐SVSCN and its selenophene‐substituted analogue f‐BSeI2g‐SVSCN with a julolidine‐functionalized benzimidazoline n‐dopant JLBI, vis‐à‐vis when blended with commercially available n‐dopants TAM and N‐DMBI. The advantages of introducing a more lipophilic julolidine group into the dopant structure of JLBI are evidenced by the enhanced OTEs performance that JLBI‐doped films show when compared to those doped with N‐DMBI or TAM. In fact, thanks to the enhanced intermolecular interactions and the lower‐lying LUMO level enabled by the increase of selenophene content in polymer backbone, JLBI‐doped films of f‐BSeI2g‐SVSCN exhibit a unprecedent σ of 206 S cm−1 and a PF of 114 μW m−1 K−2. Interestingly, σ can be further enhanced up to 326 S cm−1 by using TAM dopant as a consequence of its favorable diffusion behavior into densely packed crystalline domains. These values are the highest to date for solution‐processed molecularly n‐doped polymers, demonstrating the effectiveness of the polymer‐dopant matching approach carried out in this work. [ABSTRACT FROM AUTHOR]

Multiresonant thermally activated delayed fluorescence (MR‐TADF) emitters have been the focus of extensive design efforts as they are recognized to show bright, narrowband emission, which makes them very appealing for display applications. However, the planar geometry and relatively large singlet–triplet energy gap lead to, respectively, severe aggregation‐caused quenching (ACQ) and slow reverse intersystem crossing (RISC). Here, a design strategy is proposed to address both issues. Two MR‐TADF emitters triphenylphosphine oxide (TPPO)‐tBu‐DiKTa and triphenylamine (TPA)‐tBu‐DiKTa have been synthesized. Twisted ortho‐substituted groups help increase the intermolecular distance and largely suppress the ACQ. In addition, the contributions from intermolecular charge transfer states in the case of TPA‐tBu‐DiKTa help to accelerate RISC. The organic light‐emitting diodes (OLEDs) with TPPO‐tBu‐DiKTa and TPA‐tBu‐DiKTa exhibit high maximum external quantum efficiencies (EQEmax) of 24.4% and 31.0%, respectively. Notably, the device with 25 wt% TPA‐tBu‐DiKTa showed both high EQEmax of 28.0% and reduced efficiency roll‐off (19.9% EQE at 1000 cd m−2) compared to the device with 5 wt% emitter (31.0% EQEmax and 11.0% EQE at 1000 cd m−2). The new emitters were also introduced into single‐layer light‐emitting electrochemical cells (LECs), equipped with air‐stable electrodes. The LEC containing TPA‐tBu‐DiKTa dispersed at 0.5 wt% in a matrix comprising a mobility‐balanced blend‐host and an ionic liquid electrolyte delivered blue luminance with an EQEmax of 2.6% at 425 cd m−2. The high efficiencies of the OLEDs and LECs with TPA‐tBu‐DiKTa illustrate the potential for improving device performance when the DiKTa core is decorated with twisted bulky donors. [ABSTRACT FROM AUTHOR]

The isoindigo and its derivatives have rapidly garnered attention as widely employed electron‐deficient moieties, finding extensive applications in organic field‐effect transistors. In this study, four different isoindigo‐based organic semiconductor polymers were synthesized via a Stille coupling reaction of four isoindigo molecules with varying side chains serving as acceptors and bithiophene as donors. Furthermore, their optical, electrochemical, thermal stability, and other relevant properties were comprehensively evaluated. These polymers exhibited remarkable electrochemical and thermal stability attributed to their low LUMO energy level, which facilitates effective electrical contact between the semiconductor layer and the source/drain while ensuring excellent air stability for the semiconductor polymers. Additionally, solution‐gate field‐effect transistors prepared using these polymers achieved hole mobilities of 10−2 cm2 V−1 S−1 along with an Ion/Ioff ratio of 8.39×103, demonstrating exceptional field‐effect performance. [ABSTRACT FROM AUTHOR]

The fabrication and characterization of an all polymers‐based bulk heterojunction type organic photodiode having a narrowband response in the near‐infrared spectral region with full width at half‐maxima of 63 nm is reported. The active layer of the photodiode constitutes a 1:1 (by weight) blend of poly[4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b;4,5‐b']dithiophene‐2,6‐diyl‐alt‐(4‐(2‐ethylhexyl)‐3‐fluorothieno[3,4‐b]thiophene‐)‐2‐carboxylate‐2‐6‐diyl)] (PCE10) and poly{[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diy1]‐alt‐5,5′‐(2,2′‐dithiophene)} (N2200) deposited using solution processing. The device exhibits a linear dynamic range of 35 dB, response speed of 893 kHz, and specific‐detectivity of 109 Jones at 808 nm excitation wavelength. The narrowband response is achieved using the charge collection narrowing mechanism in a 2.7 μm thick junction device. [ABSTRACT FROM AUTHOR]

Thin films of molecular materials are commonly employed in organic light‐emitting diodes, field‐effect transistors, and solar cells. The morphology of these organic films is shown to depend heavily on the processing used during manufacturing, such as vapor co‐deposition. However, the prediction of processing‐dependent morphologies has until now posed a significant challenge, particularly in cases where self‐assembly and ordering are involved. In this work, a method is developed based on coarse‐graining that is capable of predicting molecular ordering in vapor‐deposited films of organic materials. The method is tested on an extensive database of novel and known organic semiconductors. A good agreement between the anisotropy of the refractive indices of the simulated and experimental vapor‐deposited films suggests that the method is quantitative and can predict the molecular orientations in organic films at an atomistic resolution. The methodology can be readily utilized for screening materials for organic light‐emitting diodes. [ABSTRACT FROM AUTHOR]

Inspired by the previous machine‐learning study that the number of hydrogen‐bonding acceptor (NHBA) is important index for the hole mobility of organic semiconductors, seven dithienobenzothiazole (DBT) derivatives 1 a–g (NHBA=5) were designed and synthesized by one‐step functionalization from a common precursor. X‐ray single‐crystal structural analyses confirmed that the molecular arrangements of 1b (the diethyl and ethylthienyl derivative) and 1c (the di(n‐propyl) and n‐propylthienyl derivative) in the crystal are classified into brickwork structures with multidirectional intermolecular charge‐transfer integrals, as a result of incorporation of multiple hydrogen‐bond acceptors. The solution‐processed top‐gate bottom‐contact devices of 1b and 1c had hole mobilities of 0.16 and 0.029 cm2 V−1s−1, respectively. [ABSTRACT FROM AUTHOR]

Solid‐state molecular arrangement has been recognized as the most important role in the charge transport properties of organic semiconductors. Although highly ordered molecular stacking is achieved in single crystals, maintaining single‐crystal molecular packing in solution‐processed thin films remains a significant challenge. Herein, a new type of n‐type organic semiconductors based on an asymmetric fluoranthene imide unit is reported, whose intermolecular packing and aggregation behavior in the thin film state can be effectively controlled by regulating the cyano substitution sites and alkyl chain types in the imide group. F10 with cyano groups at 4,9‐sites and branched 2‐ethylhexyl chain encouragingly shows a highly ordered single‐crystal‐like molecular packing in solution‐processed thin film after thermal annealing, and thus the resulting organic field‐effect transistors exhibit impressive charge transport performance, with the electron mobility as high as 0.116 cm2 V−1 s−1. This work opens a new avenue for developing high‐performance solution‐processed n‐type semiconductors. [ABSTRACT FROM AUTHOR]

Chemical doping is a powerful way to enhance the electrical performance of organic electronics. To avoid perturbing the ordered molecular packing of organic semiconducting hosts, molecular dopants are deposited on the surface of highly crystalline organic semiconductor thin films. However, such surface doping protocols not only limit charge‐transfer efficiency but also cause dopant diffusion problems, which significantly reduce charge carrier mobility and device stability. Here, an innovative anion bulk doping strategy is reported that allows effective doping of organic single‐crystalline films (OSCFs) without disrupting molecular ordering to improve the performance of organic field‐effect transistors (OFETs). This method is mediated by anion dopants and can be pictured as an effective charge transfer of dopants with organic semiconductors in liquid phase. The direct introduction of dopant anions overcomes limitations of partial charge transfer while avoiding interference from dopant aggregation with crystallization. Using this method, the average carrier mobility of the OSCFs is boosted by ≈2.5 times. Significantly, low‐voltage OFETs developed from anion‐doped OSCFs exhibit a near‐ideal subthreshold swing of 59.2 mV dec−1 and unparalleled mobility as high as 19.8 cm2 V−1 s−1 together with excellent stability. The concept of anion doping opens new avenues for improving the electrical performance of organic electronics. [ABSTRACT FROM AUTHOR]

Organic electrochemical transistors (OECTs) are promising candidates for artificial synapses to achieve high‐performance synaptic characteristics. While most research has focused on modifying the properties of organic semiconductors for efficient ion doping, there is a lack of systematic investigation into the relationship between ion‐mediated mechanisms and synaptic performance. In this study, an effective strategy for enhancing electrochemical doping and de‐doping by utilizing different coulombic anions is proposed. The findings reveal that doped ions in the channel layer affect inter‐ion interactions, influencing the non‐volatile effects by improving the doping performance of the synaptic device. Moreover, electrochemical analysis indicates that ions in the channel layer are sequentially de‐doped, enabling high linearity and symmetry. The fabricated devices demonstrate high‐performance synaptic properties including a retention time of ≈102 s with ≈50% retention over peak current and near‐ideal long‐term potentiation/long‐term depression (LTP/LTD) through effective electrochemical doping and de‐doping. These results show that controlling both the properties of organic semiconductors and ion interactions in the electrolyte is crucial for OECTs, opening up various applications for neuromorphic computing. [ABSTRACT FROM AUTHOR]

Upconversion detectors monolithically combining a detection unit and a light emitting unit, enables light detection and visualization in a compact structure, promising great advances in miniaturized multifunctional optoelectronics. The detection range of upconversion detectors usually covers a broadband spectrum, limiting their use in spectroscopic fields. This work investigates two wavelength‐selective upconversion detectors made with organic semiconductors to realize narrowband near‐infrared (NIR) light detection and visualization dual function. Two non‐fullerene‐based NIR‐sensitive bulk‐heterojunctions (BHJs) are exploited to make wavelength‐selective upconversion detectors, achieving peak sensitivity at 860 and 890 nm, with full width at half maximum of 125 and 170 nm, respectively. Each NIR‐sensitive BHJ comprises a donor polymer and a non‐fullerene acceptor, both of which are selectively sensitive to NIR light. The cumulative analysis of the optical properties of the absorber and current–voltage characteristics of the device indicates that the wavelength selectivity stems mainly from the wavelength‐dependent absorption. In particular, the upconversion detectors exhibit wavelength‐selective electronic and optical dual‐readouts, which are appealing for miniaturized spectroscopic applications, including health monitoring, optical communication, and microbead imaging, paving the way for practical applications. [ABSTRACT FROM AUTHOR]

Unipolar p‐ and n‐type organic field‐effect transistors (OFETs) are essential for constructing organic circuits and complementary designs crucial for high‐performance electronics. Traditionally, fabricating these transistors requires separate p‐type and n‐type organic semiconductors (OSCs), which complicates the process due to intricate patterning, protection of the first OSC layer, and considerable material wastage. In this work, an innovative approach is introduced, inspired by silicon transistor fabrication to obtain unipolar OFETs, employing a single ambipolar OSC in conjunction with doped organic semiconductor films (DOSCFs) as electrodes. This results demonstrate that OFETs with DOSCF electrodes suppress ambipolarity dramatically and achieve on/off ratios that are two to three orders of magnitude higher than those with metal electrodes, along with excellent stability. The unipolar characteristics of the devices are attributed to the unique work function properties and the intrinsic charge carrier behavior of the DOSCF electrodes. Significantly, inverter circuits utilizing these unipolar transistors outperformed traditional ambipolar transistors with metal electrodes, achieving a fivefold increase in voltage gain. This novel strategy promises to enhance the practicality and economic viability of organic electronics, paving the way for more sustainable and high‐performance circuit designs. [ABSTRACT FROM AUTHOR]

Organic semiconducting wires have captured broad attention in recent years due to its tremendous applications in various fields. The structural and chemical versatility, easy fabrication, tunable properties, and low cost have made their inevitable presence in electronics and optoelectronics. Herein, the synthesis and characteristic description of a new thiazolo[3,2‐a] hydrazone‐based organic semiconducting microwire synthesized by the Lewis acid‐based condensation reaction between methyl (Z)‐2‐(2‐(2‐methoxy‐2‐oxoethylidene)‐3‐oxo‐2,3‐dihydrothiazolo[3,2‐a]indol‐9‐yl)‐2‐oxoacetate and phenyl hydrazine under reflux conditions is reported. The optical, electrical, and semiconducting nature of the material is revealed from the specular reflectance study. When the Tauc plot analysis reveals a direct bandgap of 2.03 eV, the hot probe test suggests the nature of the majority of charge carriers as electrons, indicating the hydrazone as an organic semiconductor. The long wire‐like morphology with a high aspect ratio makes the molecule conceivable for advanced optoelectronic applications. [ABSTRACT FROM AUTHOR]

In this study, the porous graphite phase carbon nitride photocatalyst (P-g-C3N4) is prepared by the CaCO3 template method, and then P-g-C3N4/T-polyethylene terephthalate (T-PET) catalytic fibre is prepared by the padding method. P-g-C3N4 can provide more active sites than g-C3N4 as proved by the Brunauer–Emmett–Teller and the UV–Visible diffuse reflectance test. P-g-C3N4 powder catalyst successfully supports PET fibre as proved by scanning electron microscope, Fourier infrared spectroscopy and X-ray diffraction spectroscopy. The photocatalytic performance of P-g-C3N4/T-PET catalytic fibre is tested by constructing a single hexavalent chromium or hexavalent chromium/organic pollutant binary pollution system. The potential application value of P-g-C3N4/T-PET catalytic fibre is further explored by simulating the complex actual water environment. After five recycles, P-g-C3N4/T-PET catalytic fibre shows good catalytic performance. The mechanism of P-g-C3N4/PET photocatalytic degradation of organic pollutants is proposed through the capture agent experiment and electron paramagnetic resonance spectroscopy. Among them, •O2− is the most important active species of P-g-C3N4 catalytic fibre, which is used for the oxidation of organic pollutants. At the same time, photoelectrons generated by the catalytic fibre are used to reduce hexavalent chromium. The efficiency of P-g-C3N4 to remove pollutants is improved by using PET fibre as a carrier, which not only solves the problem of difficult recovery of powder catalysts but also provides more active sites. [ABSTRACT FROM AUTHOR]

In this work, naphthalenediimide (NDI) derivatives are widely studied for their semiconducting properties and the influence of the side-chain length on the crystal packing is reported, along with the thermal properties of three core-chlorinated NDIs with different fluoroalkyl side-chain lengths (CF3-NDI, C3F7-NDI and C4F9-NDI). The introduction of fluorinated substituents at the imide nitrogen and addition of strong electron-withdrawing groups at the NDI core are used to improve the NDI derivatives air stability. The new compound, CF3-NDI, was deeply analyzed and compared to the well-known C3F7-NDI and C4F9-NDI, leading to the discovery and solution of two different crystal phases, form α and solvate form, and a solid solution of CF3-NDI and CF3-NDI-OH, formed by the decomposition in DMSO. [ABSTRACT FROM AUTHOR]

In this work, we present the innovative synthesis of salophen (acetaminosalol) derivatives in a solvent-free environment by high-speed ball milling, using a non-conventional activation method, which allowed obtaining compounds in a shorter time and with a better yield. Furthermore, for the first time, the salophen derivatives were deposited as composite films, using a matrix of poly 3,4-ethylene dioxythiophene:polystyrene sulfonate (PEDOT:PSS) polymer. Significant findings include the transformation from the benzoid to the quinoid form of PEDOT post-IPA treatment, as evidenced by Raman spectroscopy. SEM analysis revealed the formation of homogeneous films, and AFM provided insights into the changes in surface roughness and morphology post-IPA treatment, which may be crucial for understanding potential applications in electronics. The optical bandgap ranges between 2.86 and 3.2 eV for PEDOT:PSS-salophen films, placing them as organic semiconductors. The electrical behavior of the PEDOT:PSS-salophen films undergoes a transformation with the increase in voltage, from ohmic to space charge-limited conduction, and subsequently to constant current, with a maximum of 20 mA. These results suggest the possible use of composite films in organic electronics. [ABSTRACT FROM AUTHOR]

The use of organic semiconductors in electronic devices, including transistors, sensors, and memories, unlocks innovative possibilities such as streamlined fabrication processes, enhanced mechanical flexibility, and potential new applications. Nevertheless, the increasing technical demand for patterning organic semiconductors requires greater integration and functional implementation. This paper overviews recent efforts to pattern organic semiconductors compatible with electronic devices. The review categorizes the contributions of organic semiconductor patterning approaches, such as surface-grafting polymers, capillary force lithography, wettability, evaporation, and diffusion in organic semiconductor-based transistors and sensors, offering a timely perspective on unconventional approaches to enable the patterning of organic semiconductors with a strong focus on the advantages of organic semiconductor utilization. In addition, this review explores the opportunities and challenges of organic semiconductor-based integration, emphasizing the issues related to patterning and interconnection. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have garnered significant interest within the scientific community due to their distinctive ability to act as organic semiconductors responsive to visible light. This unique attribute makes them up-and-coming candidates for facilitating photocatalytic organic reactions. Herein, two donor–acceptor COFs, TPE-BSD-COF and TPE-BD-COF, have been designed and synthesized by incorporating electron-rich tetraphenylethylene and electron-deficient benzoselenadiazole and benzothiadiazole units into the framework through a Schiff-base polycondensation reaction. Both COFs exhibit exceptional crystallinity and enduring porosity. TPE-BSD-COF and TPE-BD-COF exhibit broad light absorption capabilities, a narrow optical band gap, and low electrochemical impedance spectrum (EIS) levels, indicating that the two COFs are effective heterogeneous photocatalysts for the reductive dehalogenation of phenacyl bromide derivatives under blue LED irradiation. A high photocatalytic yield of 98% and 95% was achieved by TPE-BSD-COF and TPE-BD-COF catalysts, respectively, within only one hour. [ABSTRACT FROM AUTHOR]

Developing novel n‐type organic semiconductors is an on‐going research endeavour, given their pivotal roles in organic electronics and their relative scarcity compared to p‐type counterparts. In this study, a new strategy was employed to synthesize n‐type organic semiconductors featuring a fully fused conjugated backbone. By attaching two sets of adjacent amino and formyl groups to the indacenodithiophene‐based central cores and triggering a tandem reaction sequence of a Knoevenagel condensation‐intramolecular cyclization, DFA1 and DFA2 were realized. The solution‐processed organic field effect transistors based on DFA1 exhibited unipolar n‐type transport character with a decent electron mobility of ca. 0.10 cm2 V−1 s−1 (ca. 0.038 cm2 V−1 s−1 for DFA2 based devices). When employing DFA1 as a third component in organic solar cells, a high power conversion efficiency of 19.2 % can be achieved in ternary devices fabricated with PM6 : L8‐BO : DFA1. This work provides a new pathway in the molecular engineering of n‐type organic semiconductors, propelling relevant research forward. [ABSTRACT FROM AUTHOR]