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The development of nonfullerene acceptors (NFAs), represented by ITIC, has contributed to improving the power conversion efficiency (PCE) of organic solar cells (OSCs). Although tuning the electronic structures to reduce the exciton binding energy (Eb) is considered to promote photocharge generation, a rational molecular design for NFAs has not been established. In this study, we designed and developed two ITIC‐based NFAs bearing spiro‐substituted bithiophene or biphenyl units (named SpiroT‐DCI and SpiroF‐DCI) to tune the frontier molecular orbital (FMO) distribution of NFAs. While the highest occupied molecular orbitals (HOMOs) of SpiroF‐DCI and ITIC are delocalized in the main π‐conjugated framework, the HOMO of SpiroT‐DCI is distributed on the bithiophene unit. Reflecting this difference, SpiroT‐DCI exhibits a smaller Eb than either SpiroF‐DCI or ITIC, and exhibits greater external quantum efficiency in single‐component OSCs. Furthermore, SpiroT‐DCI shows improved PCEs for bulk‐heterojunction OSCs with a donor of PBDB‐T, compared with that of either SpiroT‐DCI or ITIC. Time‐resolved spectroscopy measurements show that the photo‐induced intermolecular charge separation is effective even in pristine SpiroT‐DCI films. This study highlights the introduction of spiro‐substituted bithiophene units that are effective in tuning the FMOs of ITIC, which is desirable for reducing the Eb and improving the PCE in OSCs. [ABSTRACT FROM AUTHOR]

Open‐shell organic radical semiconductor materials have received increasing attention in recent years due to their distinctive properties compared to the traditional materials with closed‐shell singlet ground state. However, their poor chemical and photothermal stability in ambient conditions remains a significant challenge, primarily owing to their high reactivity with oxygen. Herein, a novel open‐shell poly(3,4‐dioxythiophene) radical PTTO2 is designed and readily synthesized for the first time using low‐cost raw material via a straightforward BBr3‐demethylation of the copolymer PTTOMe2 precursor. The open‐shell character of PTTO2 is carefully studied and confirmed via the signal‐silent 1H nuclear magnetic resonance spectrum, highly enhanced electron spin resonance signal compared with PTTOMe2, as well as the ultra‐wide ultraviolet‐visible‐near nfraredUV–vis–NIR absorption and other technologies. Interestingly, the powder of PTTO2 exhibits an extraordinary absorption range spanning from 300 to 2500 nm and can reach 274 °C under the irradiation of 1.2 W cm−2, substantially higher than the 108 °C achieved by PTTOMe2. The low‐cost PTTO2 stands as one of the best photothermal conversion materials among the pure organic photothermal materials and provides a new scaffold for the design of stable non‐doped open‐shell polymers. [ABSTRACT FROM AUTHOR]

Edible electronics is emerging in recent years motivated by a diverse number of healthcare applications, where sensors can be safely ingested without the need for any medical supervision. However, the current lack of stable and well‐performing edible semiconductors needs to be addressed to reach technological maturity and allow the surge of a new generation of edible circuits. In the quest for good‐performing edible semiconductors, this study has explored the possibility of considering materials that are not regulated for intentional ingestion, yet are daily swallowed with no adverse reactions, such as pigments contained in toothpaste. This work first elaborates on the basis of inadvertent ingestion data to estimate the quantity of daily ingested Copper(II) Phthalocyanine (CuPc), a whitening pigment and well‐known organic semiconductor. Subsequently, CuPc is employed in the first demonstration of fully edible electrolyte‐gated transistors operating at low voltage (<1 V), displaying good reproducibility and stable performance for over a year. The results indicate that, with the daily ingested quantity of CuPc from toothpaste, more than 104 edible transistors can be realized, thus paving the way to edible circuits, a critical component of future edible electronic systems. [ABSTRACT FROM AUTHOR]

Photosensitive field‐effect transistors (PhFETs) are three‐terminal photodetectors that enable photocurrent modulation and amplification through gate‐voltage control. Organic‐inorganic hybrid perovskites are known for their high photoelectric conversion efficiency, but ion migration in these materials causes gate‐field shielding, posing challenges for constructing PhFETs using only 3D perovskites. To address this issue, a heterojunction strategy is proposed using the stable and process‐compatible organic semiconductor poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) as the channel layer and the organic‐inorganic hybrid perovskite cesium‐doped formamidinium lead trihalide (FA0.9Cs0.1PbI3) as the light absorption layer. The bottom‐gate top‐contact PhFETs are fabricated using all‐solution processes. By comparing PhFET performance across three active‐layer structures (perovskite, P3HT, perovskite/P3HT) under dark and illuminated conditions, it is found that perovskite devices basically do not exhibit field‐effect but have the highest light‐to‐dark current ratio; P3HT devices exhibit field‐effect but weak photoresponse at 532 nm; in contrast, P3HT/perovskite heterojunction devices not only achieve field‐effect but also exhibit substantial photoresponse. The P3HT channel effectively modulates or amplifies the photocurrent and dark current of the heterojunction device, yielding nearly ten‐fold enhancements in responsivity and external quantum efficiency compared to perovskite devices, along with significantly improved response speed. This study advances the development of 3D organic‐inorganic hybrid perovskite PhFETs. [ABSTRACT FROM AUTHOR]

The rise of artificial intelligence and the Internet of Things have spurred an increasing demand for wearable, sustainable, and maintenance‐free power sources. Organic thermoelectric (OTE) devices are emerged as promising candidates because they are capable of converting heat energy into electricity directly without the need of moving parts, capable of flexible and seamless integration with multifunctional miniaturized electronics. In addition, OTE devices can perform straightforward as various self‐powered sensors, boosting their applications in the field of intelligent interactions. This review focuses on recent advances in OTE materials and devices for applications in energy harvesting and sensing. The basic knowledge and key parameters of OTE materials and devices are presented, followed by detailed introduction of recent progress of OTE generators, sensors, and other OTE‐integrated devices. Next, several aspects of optimizing OTE devices toward multifunctional applications are highlighted. Finally, an overview of the current challenges and future research directions of OTE‐based devices is addressed. It is hoped that this review can pave the way for speeding up a bright future for the development and practical applications of OTE devices. [ABSTRACT FROM AUTHOR]

The burgeoning field of conjugated microporous polymers (CMPs) has generated widespread interest due to their potential as photocatalysts for hydrogen production from water. Nevertheless, their photocatalytic performance is sometimes hindered by inadequate charge separation and transfer, coupled with rapid charge recombination. Herein, a strategy to enhance photocatalytic performance via the customization of π‐bridges through the modulation of heteroatoms in a series of donor‐π‐acceptor (D‐π‐A) CMPs is proposed. This affords optimized energy levels and improved charge separation and transfer, thus boosting photocatalytic efficiency. Among various heteroatom substitutions, S‐doped CMP (10 mg) demonstrates the highest photocatalytic hydrogen evolution rate of 203 µmol h−1 (AQY450nm = 7.4%) under visible light irradiation. Subsequent experimental analysis reveals its superior photocatalytic performance can be largely related to its minimized exciton binding energy, facilitated charge transfer efficiency, and impeded charge recombination among these heteroatom‐doped D‐π‐A CMPs. This research paves the way for the rational design and modification of organic semiconductors for advanced solar‐driven photocatalysis by promoting charge separation and transfer. [ABSTRACT FROM AUTHOR]

Efficient and air‐stable molecular dopants are critical for optimizing the performance of thermoelectric devices. Despite significant advancements in developing p‐dopants for organic semiconductors, the quest for efficient and air‐stable n‐dopants remains challenging. Here, viologen‐tetraarylborate (VT) is introduced as a promising n‐dopant for thermoelectric applications, demonstrating its remarkable photo‐activation efficiency. After just 1 min of light exposure, a maximum power factor of 8.6 µW m−1 K−2, with a conductivity of 0.86 S cm−1 and a Seebeck coefficient of −346 µV K−1, is achieved for the VT doped PNDI2TEG‐2Tz film. Furthermore, VT exhibits excellent air stability, simplifying the device preparation process by allowing films to be prepared in ambient conditions. Additionally, the unique doping mechanism imparts good air stability to the stock solution of VT and the conjugated polymer, ensuring that the storage time of the stock solution does not affect thermoelectric performance. This innovative approach not only highlights the potential of VT as an efficient n‐dopant but also paves the way for developing novel air‐stable dopants and advancing doping methodologies in thermoelectric material research. [ABSTRACT FROM AUTHOR]

Porphyrin and its derivatives have been seen as a type of potential organic photocatalyst for photocatalytic hydrogen evolution. Substituent regulation as a simple method can effectively regulate the photoelectric characteristic of organic semiconductors. Herein, we designed three porphyrin derivatives attached with different substituents (PP‐NH2, PP‐OH and PP‐COOH). Through a facile substituent optimization strategy, the photoelectric properties of these porphyrin derivatives show an obvious difference, which leads an optimized photocatalytic hydrogen evolution efficiency. The porphyrin derivative with carboxyl presents a reduced impedance, and a better charge separation. Compared to the amino group, PP‐COOH with carboxyl, achieved a high hydrogen evolution rate of 2.20 mmol g−1 h−1 (over 20 times than that of PP‐NH2). Moreover, enhanced stability was observed in PP‐COOH rather than PP‐OH, because of the lower HOMO energy level. And the ionization of carboxyl in water negatively charges the porphyrin derivatives and forms a relatively stable sol. This result further increases the operation stability of PP‐COOH, during photocatalytic hydrogen evolution. This study presents a promising design strategy for long‐lifetime photocatalysts for hydrogen evolution. [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]

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]

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]

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]

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]

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]

As the world strives toward its net‐zero targets, innovative solutions are required to reduce carbon emissions across all industrial sectors. One approach that can reduce emissions from food production is agrivoltaics—photovoltaic devices that enable the dual‐use of land for both agricultural and electrical power‐generating purposes. Optimizing agrivoltaics presents a complex systems‐level challenge requiring a balance between maximizing crop yields and on‐site power generation. This balance necessitates careful consideration of optics (light absorption, reflection, and transmission), thermodynamics, and the efficiency at which light is converted into electricity. Herein, real‐world solar insolation and temperature data are used in combination with a comprehensive device‐level model to determine the annual power generation of agrivoltaics based on different photovoltaic material choices. It is found that organic semiconductor‐based photovoltaics integrated as semitransparent elements of protected cropping environments (advanced greenhouses) have comparable performance to state‐of‐the‐art, inorganic semiconductor‐based photovoltaics like silicon. The results provide a solid technical basis for building full, systems‐level, technoeconomic models that account for crop and location requirements, starting from the undeniable standpoint of thermodynamics and electro‐optical physics. [ABSTRACT FROM AUTHOR]

Sp2‐carbon (sp2‐c) covalent organic frameworks (COFs), featuring distinctive π‐conjugated network structures, facilitate the migration of photo‐generated carriers, rendering them exceptionally appealing for applications in photoelectrochemical water splitting. However, owing to the powdery nature of COFs, leaving anchor the sp2‐c COFs powder tightly onto a conductive substrate challenging. Here, we propose a method for preparing photoactive substance‐conductive substrate integrated photocathodes through copper surface‐mediated knoevenagel polycondensation (Cu‐SMKP), this approach results in a uniform and stable sp2‐c COF film, directly grown on commercial copper foam (COFTh‐Cu). The COFTh‐Cu demonstrates a high H2‐evolution photocurrent density of 56 μA cm−2 at 0.3 V vs. RHE, sustaining stability for 12 h. The as‐prepared COFTh‐Cu represents a 4.5‐fold increase in current density compared to traditional spin‐coating methods and outperforms most COF photocathodes without cocatalysts. This innovative copper surface‐mediated approach for preparing photocathodes opens up a crucial pathway towards the realization of highly active COF photocathodes. [ABSTRACT FROM AUTHOR]

Organic solar cells (OSCs) are gaining attention in building‐integrated and agricultural photovoltaics due to their light weight, mechanical flexibility, and low‐cost solution processability. To achieve commercial viability, understanding the relationships between active layer material structure, film morphology, and photovoltaic performance is crucial. Nanoscale infrared spectroscopy coupled with atomic force microscopy (nanoIR‐AFM) offers an advanced characterization of active layer morphology at high resolution to help understand OSC performance. This review outlines recent developments and applications of nanoIR‐AFM in OSC research, detailing its principles, instruments, and functions. Strategies to enhance OSC performance and their morphological characterization by nanoIR‐AFM are discussed, offering insights into active layer evolution and device performance. The review highlights challenges faced by nanoIR‐AFM in OSC applications and highlights its potential role in advancing OSC technology. As nanoIR‐AFM continues to evolve, it will play a critical role in OSC development, providing essential technical means for further progress. [ABSTRACT FROM AUTHOR]

exo‐6b2‐Methyl‐substituted pentabenzocorannulene (exo‐PBC‐Me) was synthesized by the palladium‐catalyzed cyclization of 1,2,3‐triaryl‐1H‐cyclopenta[l]phenanthrene. Its bowl‐shaped geometry with an sp3 carbon atom in the backbone and a methyl group located at the convex (exo) face was verified by X‐ray crystallography. According to DFT calculations, the observed conformer is energetically more favorable than the endo one by 39.9 kcal/mol. Compared to the nitrogen‐doped analogs with intact π‐conjugated backbones (see the main text), exo‐PBC‐Me displayed a deeper bowl depth (avg. 1.93 Å), redshifted and broader absorption (250–620 nm) and emission (from 585 to more than 850 nm) bands and a smaller optical HOMO–LUMO gap (2.01 eV). exo‐PBC‐Me formed polar crystals where all bowl‐in‐bowl stacking with close π ⋅ ⋅ ⋅ π contacts is arranged unidirectionally, providing the potential for applications as organic semiconductors and pyroelectric materials. This unusual structural feature, molecular packing, and properties are most likely associated with the assistance of the methyl group and the sp3 carbon atom in the backbone. [ABSTRACT FROM AUTHOR]

The energetic driving force for electron transfer must be minimized to realize efficient optoelectronic devices including organic light‐emitting diodes (OLEDs) and organic photovoltaics (OPVs). Exploring the dynamics of a charge‐transfer (CT) state at an interface leads to a comprehension of the relationship between energetics, electron‐transfer efficiency, and device performance. Here, we investigate the electron transfer from the CT state to the triplet excited state (T1) in upconversion OLEDs with 45 material combinations. By analyzing the CT emission and the singlet excited‐state emission from triplet–triplet annihilation via the dark T1, their energetics and electron‐transfer efficiencies are extracted. We demonstrate that the CT→T1 electron transfer is enhanced by the stronger CT interaction and a minimal energetic driving force (<0.1 eV), which is explained using the Marcus theory with a small reorganization energy of <0.1 eV. Through our analysis, a novel donor–acceptor combination for the OLED is developed and shows an efficient blue emission with an extremely low turn‐on voltage of 1.57 V. This work provides a solution to control interfacial CT states for efficient optoelectronic devices without energy loss. [ABSTRACT FROM AUTHOR]

The development of electron transport and n‐type materials is still largely dominated by a limited number of organic semiconductors, with fullerenes at the forefront. In contrast, substantial progress has been made in developing hole transport and p‐type materials. Therefore, expanding the range of electron acceptors, making them solution‐processable, and elucidating their structural arrangement by X‐ray crystallography is essential. We synthesised 2,2'‐bi‐(5,6,11,12‐tetraazanaphthacene) (bi‐TANC) and its triptycene end‐capped derivative, 2,2′‐bi(8,13‐dihydro‐8,13‐[1,2]benzenonaphtho‐5,6,15,16‐tetraazanaphthacene) (bi‐TpTANC), as electron acceptors. Bi‐TANC exhibits a herringbone‐like crystal packing with intermolecular π–π overlap, which is observed in typical organic n‐type semiconductors. However, it showed poor solubility, similar to larger acenes. In contrast, bi‐TpTANC exhibited favourable solubility, and its electrochemistry in solution was investigated. In the cyclic voltammogram of bi‐TpTANC, reversible redox waves corresponding to 3‐step/4‐electron transfer were observed at −0.795 V (1e−), −0.927 V (1e−), and −1.44 V (2e−) as half‐wave potentials. The redox wave associated with the two‐electron transfer on the negative low‐potential side indicates the presence of through‐bond charge delocalisation in the monoanionic state. Furthermore, the LUMO level of bi‐TpTANC is −4.1 eV, which indicates its potential as a promising air‐stable n‐type material. [ABSTRACT FROM AUTHOR]

6,13‐Diethynylpentacene derivatives with sterically bulky substituents (Tr*, tris(3,5‐di‐tert‐butylphenyl)methyl groups) appended to the ethynyl moieties at the 6‐ and 13‐positions have been synthesized, as well as derivatives with electron‐withdrawing fluorine groups on the 1,2,3,4,8,9,10,11‐positions. These molecules are designed to investigate relationships between steric and electronic effects on the stability of pentacene toward endoperoxide formation via reaction with photosensitized oxygen in solution under ambient light (i. e., ‘laboratory’ conditions). It is evident from the study that stabilization through changes to the electronic characteristics of pentacene are more effective than the incorporation of sterically bulky groups at the acetylenic termini. Selected pentacene derivatives have been made into binary, amorphous films with the fullerene derivative PCBM to investigate the stability imparted by substituents against cycloaddition reactions. Overall, the introduction of steric protection through the incorporation of Tr* groups is not an efficient strategy for enhancing the persistence of pentacenes. Stabilization through fluorination proves successful for extending the lifetime of the pentacene derivatives by an order of magnitude in solution. Notably, the persistence of pentacene derivatives in solution can also be enhanced through the use of ethereal solvents stabilized with butylated hydroxy toluene (BHT) and/or an increased number of trialkylsilyl groups as substituents. [ABSTRACT FROM AUTHOR]

Excited‐state intramolecular proton transfer (ESIPT) chromophores have attracted considerable attention as promising gain media for organic lasers, particularly in amplified spontaneous emission (ASE) due to their advantageous characteristics. These include an intrinsic four‐level photocycle, significant separation between absorption and emission spectra, and enhanced emission efficiency facilitated by aggregate‐induced emission. This study investigates the amplification of π‐conjugation in hydroxyphenyl‐benzothiazole (HBT)‐based ESIPT materials via dimerization to intensify ESIPT processes, surge absorption cross‐section, enhance optical gain, and induce a redshift in emission spectra. Computational study shows that the ESIPT processes of the new dimers proceed through single proton transfer where the second proton transfer is not accessible. While the ESIPT photocycle does not extend to both HBT moieties of the dimers, the dimers foster more efficient ESIPT processes in both solution and solid states than their parent HBT, resulting in substantial Stokes shifts (>233 nm). Moreover, both dimers exhibit enhanced solid‐state photoluminescence quantum yields, reaching up to ≈55%, and low solid‐state ASE threshold values (≈6.8 µJ cm−2) in the red region. Remarkably, the new dimers demonstrate excellent thermal and photostability with notably reduced spectral overlap compared to their parent, highlighting the potential utility of the approaches to developing new organic solid‐state laser materials. [ABSTRACT FROM AUTHOR]

In organic field‐effect transistors (OFETs) using disordered organic semiconductors, interface traps that hinder efficient charge transport, stability, and device performance are inevitable. Benchmark poly(9,9‐dioctylfuorene‐co‐bithiophene) (F8T2) liquid‐crystalline polymer semiconductor has been extensively investigated for organic electronic devices due to its promising combination of charge transport and light emission properties. This study demonstrates that high‐capacitance single‐layered ionic polyurethane (PU) dielectrics enable enhanced charge transport in F8T2 OFETs. The ionic PU dielectrics are composed of a mild blending of PU ionogel and PU solution, thereby forming a solid‐state film with robust interfacial characteristics with semiconductor layer and gate electrode in OFETs and measuring high capacitance values above 10 µF cm−2 owing to the combined dipole polarization and electric double layer formation. The optimized fabricated ionic PU‐gated OFETs exhibit a low‐voltage operation at −3 V with a remarkable hole mobility of over 5 cm2 V–1 s–1 (average = 2.50 ± 1.18 cm2 V–1 s–1), which is the highest mobility achieved so far for liquid‐crystalline F8T2 OFETs. This device also provides excellent bias‐stable characteristics in ambient air, exhibiting a negligible threshold voltage shift of −0.03 V in the transfer curves after extended bias stress, with a reduced trap density. [ABSTRACT FROM AUTHOR]

Two‐photon Polymerization (2PP) process for high‐resolution 3D printing presents an opportunity to design micro‐scale structures with a high surface‐to‐volume ratio for highly responsive devices. However, these acrylate or thiol‐based resins are electrically insulating and non‐functional in nature, therefore limiting their widespread application in biosensing and biotechnology. Here, a novel conductive polymeric composite resin to print conductive 3D micro‐structures via the 2PP technique is developed and its application in sensing are demonstrated. The composite consists of acrylate‐based 2PP resin and Poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS), a conductive and biocompatible organic semiconductor The PEDOT:PSS incorporation in resin through Raman and X‐ray photoelectron spectroscopy (XPS) is studied. An electrical conductivity of 3.5 × 102 S cm−1 in a 20 µm long and 10 µm high 3D printed micro‐structure which is suitable for electronic applications is achieved. An ultra‐fast micro‐3D printed humidity sensor with a response and recovery time of 0.15 and 0.3 s respectively is demonstrated. The printed sensors show high sensitivity in humidity levels of 0–80%RH. As a proof of concept, the real‐time respiration of a human body is recorded, implying a potential application in health monitoring systems. [ABSTRACT FROM AUTHOR]

Multi‐phenyl and multi‐thiophene rod‐like molecules are typically used for weak epitaxial growth (WEG) of highly ordered organic semiconductor films enabling controllable microstructure properties and improved device performance. However, very few templating molecules have been reported, making it challenging to establish structure‐property relationships. As semiconductors are integrated into organic thin film transistors (OTFTs), the impact of templating layers on semiconductor microstructure and device performance must be established. Herein, four aromatic molecules with similar structure to para‐sexiphenyl (p‐6P) are synthesized and incorporated as the template layer in bis (pentafluoro phenoxy) silicon phthalocyanine (F10‐SiPc) OTFTs. The use of fluorinated p‐6P (p‐6PF) yields devices with the highest electron field‐effect mobility of 0.14 cm2 V−1 s−1 while a partially fluorinated p‐6P (p‐6PF4) results in improved threshold voltage. X‐ray diffraction (XRD) demonstrates varying F10‐SiPc crystallinity with choice of templating layer with the most crystalline films resulting from the use of p‐6PF. By grazing incidence wide angle X‐ray scattering (GIWAXS) and polarized Raman microscopy, all templating layers yield films with F10‐SiPc molecules predominantly aligned face‐on to the substrate. However, rod‐like p‐6P derivatives increased the face‐on orientation of F10‐SiPc. This study highlights the importance of template layer selection and deposition optimization in WEG‐based OTFTs. [ABSTRACT FROM AUTHOR]

Organic photoelectrochemical transistor (OPECT) biosensor have become an advanced bioanalytical technology due to their superior performance. In this work, a novel target‐induced bipedal DNA walker‐mediated and In2S3/Ti3C2 (MXene) Schottky junction‐gated OPECT aptasensor is developed. The DNA walker is activated by recognition between the aptamer and the target, and then moved along a predetermined orbital interface, realizing the integration of target recognition and signal amplification detection, thus obtaining higher detection sensitivity and shorter detection duration. To validate the innovative nature of OPECT bioassays, signals are obtained on OPECT‐specific detection of dibutyl phthalate (DBP) as a target molecule through alkaline phosphatase ‐mediated ascorbic acid (AA) enrichment at the In2S3/MXene photosensitive gate. AA enrichment effectively depleted holes and enhanced the photoelectric response by inhibiting electron‐hole pair complexation, realizing effective modulation of the organic semiconductor poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate). The presented OPECT aptasensor achieved sensitive detection of DBP and provided a low detection limit of 0.18 fM based on the homogeneous, well‐integrated nature of aptamer recognition. Considering the detection of different toxicant molecules, it is expected to serve as a generalized tool with excellent performance. [ABSTRACT FROM AUTHOR]

Guided nanowires grown on polymer surfaces facilitate their seamless integration as flexible devices without post‐growth processing steps. However, this is challenging due to the inability of polymer films to provide the required lattice‐matching effect. In this work, this challenge is addressed by replicating highly aligned nanogrooves from a compact disc (CD) onto a casted flexible polydimethylsiloxane (PDMS) surface. Leveraging the replicated nanogrooves, copper hexadecafluorophthalocyanine (F16CuPc) and various metal phthalocyanines are guided into large‐area, self‐aligned nanowires. Subsequently, by employing specifically designed shadow masks during electrode deposition, these nanowires are seamlessly integrated as either a monolithic flexible photodetector with a large sensing area or on‐chip flexible photodetector arrays. The resulting flexible photodetectors exhibit millisecond and long‐term stable response to UV–vis–NIR light. Notably, they demonstrate exceptional bending stability, retaining stable and sensitive photoresponse even at a curvature radius as low as 0.5 cm and after enduring 1000 bending cycles. Furthermore, the photodetector array showcases consistent sensitivity and response speed across the entire array. This work not only proves the viability of guided nanowire growth on flexible polymer surfaces by replicating CD nanogrooves but also underscores the potential for large‐scale monolithic integration of guided nanowires as flexible devices. [ABSTRACT FROM AUTHOR]

The key roles of electrode/semiconductor and semiconductor/dielectric interfaces play in the ideality of organic field‐effect transistors (OFETs) by traditional device preparation technologies are not yet fully understood, which severely limits progress in the design of molecules, the understanding of transport mechanisms, and the circuit applications of OFETs. Herein, at a quantitative level, the origin of nonideal current–voltage (I–V) curves and possibly overestimated mobility in single‐crystal OFETs is revealed, including contact resistance (Rc), charge trapping, and scattering at interfaces of devices. Impressively, an efficient interface collaborative strategy, which consists of transferred “doped” electrodes with tunable contact “doping” localized regions at the source‐drain contacts and polymer‐modified SiO2 with suitable surface polarity (γsp) is further demonstrated that have great advantages in the construction of ideal high mobility devices. Also, an interesting double‐edged sword effect of γsp of dielectric on the ideality of OFETs is observed. The dielectric with a lower γsp can result in higher mobility, while too low γsp would degrade the device ideality due to significant effect of charge scattering. The findings not only provide new perspectives and strategies to construct ideal OFETs but also offer useful guidance to correctly evaluate organic semiconductor materials. [ABSTRACT FROM AUTHOR]

Diketopyrrolopyrrole (DPP)‐based polymer semiconductors have drawn great attention in the field of organic electronics due to the planar structure, decent solubilizing capability, and high crystallinity. However, the electron‐deficient capacity of DPP derivatives are not strong enough, leading to relatively high‐lying lowest unoccupied molecular orbital (LUMO) energy levels of the corresponding polymers. As a result, n‐type and ambipolar DPP‐based polymers are rare and their electron mobilities also lag far behind the p‐type counterparts, which limits the development of important p‐n‐junction‐based electronic devices. Therefore, new design strategies have been proposed recent years to develop n‐type/ambipolar DPP‐based polymers with improved performances. In this view, these molecular design strategies are summarized, including copolymerization of DPP with different acceptors and weak donors, DPP flanked aromatic ring modification, DPP‐core ring expansion and DPP dimerization. The relationship between the chemical structures and organic thin‐film transistor performances is intensively discussed. Finally, a perspective on future trends in the molecular design of DPP‐based n‐type/ambipolar polymers is also proposed. [ABSTRACT FROM AUTHOR]

This study reports the serendipitous discovery of intermolecular anionic mixed‐valence (MV) and π‐dimer species in ortho‐pentannulated BisAzaCoroneneDiimides (BACDs) during their electrochemical reduction in a non‐aqueous solvent. A library of nitrogen‐containing extended PDIs was synthesized via an aza‐benzannulation reaction followed by a Pd‐catalysed ortho‐pentannulation reaction. Ortho‐pentannulated BACDs revealed strong aggregation abilities in solution. Concentration‐dependent UV/Vis absorption spectra, variable temperature 1H NMR experiments, and atomic force microscopy coupled to molecular dynamics support their self‐assembly into columnar aggregates. Cyclic voltammetry experiments in dichloromethane reveal prominent splitting of the first reduction wave, attributed to the formation of unprecedented intermolecular anionic MV and π‐dimers in organic solvent. These species were thoroughly characterized by real‐time spectroelectrochemistry, electrochemical simulations and theoretical calculations. Remarkably, this work underscores the tuneable nature of AzaBenzannulatedPerylene Diimides (AzaBPDIs) and BACDs, emphasizing their potential as a promising scaffold for designing supramolecular materials with long‐range radical anion delocalization. The observation of this phenomenon provides insights into the fundamental behaviour of supramolecular organic semiconductors, thereby paving the way for the development of novel electronic devices and electron‐deficient materials. [ABSTRACT FROM AUTHOR]

Opto‐electronic properties and device performance of organic semiconductors are mainly determined by energy levels of their frontier molecular orbitals, e.g. lowest unoccupied molecular orbital (ELUMO) and highest occupied molecular orbital (EHOMO) in the ground state, first singlet state (ES1) and first triplet state (ET1) in the excited state. These energy levels are always intricately intertwined. Herein, we report a series of monodisperse oligomers based on double B←N bridged bipyridine (BNBP) units. With the increasing number of repeating units, the oligomers exhibit gradually downshifted ELUMO and nearly unchanged EHOMO due to the different distribution of the frontier molecular orbitals of the oligomers. Moreover, the oligomers exhibit gradually decreasing ES1 and nearly unchanged ET1 because of the different contributions of the charge transfer component in the excited state. This work provides new insight into energy level tuning of organic semiconductors, which is important for high‐performance organic opto‐electronic devices. [ABSTRACT FROM AUTHOR]

The introduction of a colorless function to organic electronic devices allows responses to light in the near‐infrared (NIR) region and is expected to broaden the applications of these devices. However, the development of a colorless NIR dye remains a challenge due to the lack of a rational molecular design for controlling electronic transitions. In this study, to suppress the π‐π* transitions in the visible region, polycyclic donor‐acceptor‐donor π‐conjugated molecules with boron bridges (Py‐FNTz‐B and IP‐FNTz‐B) are designed and synthesized, which contain pyrrole or indenopyrrole as donor units with fluorinated naphthobisthiadiazole (FNTz) as an acceptor unit. The pyrrole end‐capped Py‐FNTz‐B shows an absorption band in the NIR region without distinct visible‐light absorption, which has led to the establishment of colorless characteristics. The indenopyrrole end‐capped IP‐FNTz‐B shows a narrow optical energy gap of 0.87 eV in films. Time‐resolved microwave conductance and field‐effect transistors demonstrate the semiconducting characteristics of these molecules, and Py‐FNTz‐B‐based devices function as NIR phototransistors. Theoretical analyses indicate that the combination of a polyene‐like electronic structure with orbital symmetry is important to obtain NIR wavelength‐selective absorption. This study suggests that a molecular design based on electronic structures can be effective in the development of colorless NIR‐absorbing dyes for organic electronics. [ABSTRACT FROM AUTHOR]

Conjugated polymers with integrating properties of delayed fluorescence and photovoltaic responses simultaneously are scarcely reported due to the generally contradictory requirements for molecular structures to achieve the two properties. Herein, an O‐B(F)←N functionalized fused unit (M) with multiple resonance features, small energy gap between lowest singlet excited state (S1) and triplet excited state (T1) (ΔEST = 0.23 eV), and delayed fluorescence (τD = 0.75 µs), is designed. Selecting three benzodithiophene (BDT) derivatives as co‐units to copolymerize with M, leading to a series of O‐B(F)←N embedded polymers also maintaining delayed fluorescence (τD = 0.4–0.5 µs). Moreover, p‐type semiconductor characteristics are tested for these polymers with hole mobilities in the range of 10−6–10−5 cm2/Vs. Devices with obviously photovoltaic responses are prepared using these polymers as donors and Y6 as the acceptor, affording a preliminary efficiency of 5.05%. This work successfully demonstrates an effective strategy to design conjugated polymers with integrating properties of delayed fluorescence and photovoltaic performance simultaneously by introducing O‐B(F)←N functional groups to polymer backbones. [ABSTRACT FROM AUTHOR]

The increasing amount of electronic exerts a profound impact on both the environment and human health. Looking forward, it is imperative to develop electronic products that can degrade under mind condition, which largely relies on the development of degradable organic semiconductors (OSCs). Yet, designing degradable OSCs with decent electrical properties is challenging. In this study, two degradable n‐type OSCs based on a dynamic covalent C═C bond formed via the Knoevenagel condensation reaction are reported. The cleavage of Knoevenagel formed C═C bond through a retro‐Knoevenagel process imparts the degradability of these two OSCs in the weak base, particularly in the human‐friendly α‐amino acid of lysine. Meanwhile, the C═C bond formed by Knoevenagel reaction preserves optimal backbone planarity and good electron delocalization of the molecules. This, in turn, endows the OSCs with commendable electron transport performance, achieving an electron mobility of up to 0.57 cm2 V⁻¹ s⁻¹ in organic thin‐film transistors. This work provides a new insight into the molecular design strategy for the development of OSCs with degradability and good electrical properties. [ABSTRACT FROM AUTHOR]