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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.

Over the past decades, organic electronics have attracted wide research attention in transistors. One of the devices is organic field effect transistors (OFET), which brought a great revolution for their excellent mechanical flexibility, lightweight, low-temperature deposition, low manufacturing cost and conformable large coverage area, in contrast to conventional silicon-based transistors. This paper highlights the overview of OFET structure, operation and electrical parameters that affect the performance. The influence of gate dielectric thickness, electrode width and channel length on the behavior of transistors in terms of threshold voltage, current ratio and saturation mobility value has also been discussed. The progress in the development of organic semiconductor materials is also outlined, which helps to resolve the power consumption issue. [ABSTRACT FROM AUTHOR]

A p-type (DiketoPyrroloPyrrole as organic semiconductor) Dual Gate OFET based biosensor is proposed for the detection of biomolecules in the nanocavity provided at the source end underlapping the region of the structure both at the top and at the bottom. Various biomolecules have been investigated for their effect on Drain current, ID which is a measure of sensitivity of the device. This device is then compared with different organic p-type semiconductor materials such as pentacene and tetracene based OFET biosensor. Drain current and sensitivity of these devices have also been calculated which shows that DPP (DiketoPyrroloPyrrole) based OFET biosensor has higher sensitivity of 3.0 x 10³ as compared to pentacene and tetracene based OFET biosensors. Simulation of these devices has been done in SILVACO ATLAS TCAD tool. The simulation results also show that the proposed device even shows higher sensitivity for high-k dielectrics such as HfO2, Ta2O5, TiO2. [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]

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. [ABSTRACT FROM AUTHOR]

Conjugated polymers exhibit significant potential for use in gas sensors owing to their flexibility and straightforward preparation. However, the performance of organic gas sensors based on such materials is currently suboptimal owing to their poor charge‐transport properties and limited selectivity. To address this limitation, a novel strategy that involves blending a chemically modified metal–organic framework (MOF) material, UiO‐66, with a conjugated polymer is developed. The MOF porous material is chemically modified with polar nitrogen‐containing functional groups (amino and nitro groups) to create gas molecule adsorption sites. To evaluate the impact of these modifications on the sensing performance, experiments that combined the sensing performance with a density functional theory simulation are conducted. The findings reveal that gas sensors fabricated using an amine‐functionalized MOF blended with conjugated polymers exhibit significantly higher sensitivity than home polymer devices, the sensing performance of the UiO‐66‐NH2/P3HT blend film improved by a factor of two with a sensitivity of ≈2%/ppm and an LOD of 0.001 ppt. Additionally, these devices exhibit exclusive NO2‐sensing performance for other gases such as CO2 and SO2. [ABSTRACT FROM AUTHOR]

Abstract Conjugated polymers exhibit significant potential for use in gas sensors owing to their flexibility and straightforward preparation. However, the performance of organic gas sensors based on such materials is currently suboptimal owing to their poor charge‐transport properties and limited selectivity. To address this limitation, a novel strategy that involves blending a chemically modified metal–organic framework (MOF) material, UiO‐66, with a conjugated polymer is developed. The MOF porous material is chemically modified with polar nitrogen‐containing functional groups (amino and nitro groups) to create gas molecule adsorption sites. To evaluate the impact of these modifications on the sensing performance, experiments that combined the sensing performance with a density functional theory simulation are conducted. The findings reveal that gas sensors fabricated using an amine‐functionalized MOF blended with conjugated polymers exhibit significantly higher sensitivity than home polymer devices, the sensing performance of the UiO‐66‐NH2/P3HT blend film improved by a factor of two with a sensitivity of ≈2%/ppm and an LOD of 0.001 ppt. Additionally, these devices exhibit exclusive NO2‐sensing performance for other gases such as CO2 and SO2.

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.

In this work, the synthesis of BODIPY-phenyl-triazole labelled coumarins (BPhTCs) using a two-step approach is described. The influence of the BODIPY appending on the photophysical, electrochemical and thermal properties of the phenyl-triazole-coumarin precursors (PhTCs) was investigated. Band gap energies were measured by absorption spectroscopy (2.20 ± 0.02 eV in the solid and 2.35 ± 0.01 eV in solution) and cyclic voltammetry (2.10 ± 0.05 eV). The results are supported by DFT calculations confirming the presence of lowest LUMO levels that facilitate the electron injection and stabilize the electron transport. Their charge-transport parameters were measured in Organic Field-Effect Transistor (OFET) devices. BPhTCs showed an ambipolar transistor behavior with good n-type charge mobilities (10−2 cm2V−1s−1) allowing these derivatives to be employed as promising semiconducting crystalline and fluorescent materials with good thermal and air stability up to 250 °C.

A series of thieno[3,2- b ]thiophene (TT) flanked para -azaquinodimethane (p -AQM) based quinoidal conjugated polymers PAQM2TT-T , PAQM2TT-BT and PAQM3TT were designed in a strategy to extend the aromatic-quinoidal π-system. The three polymers were synthesized by Stille polycondensation, and their opto-electronic properties and device performance in field-effect transistors have been explored. From absorption spectroscopy, the polymers show low bandgaps (1.54–1.57 eV) and high HOMO energy levels. They exhibit typical p-type behavior according to the results of the characterization of the field-effect transistors with average charge carrier mobilities of 0.08 cm2 V−1 s−1 for PAQM2TT-T , 0.12 cm2 V−1 s−1 for PAQM2TT-BT and 0.05 cm2 V−1 s−1 for PAM3TT. This report presents an alternative π-extended quinoidal-donor strategy to control the molecular design and properties of new p -AQM-based conjugated polymers. • A novel monomer unit containing thienothiophene and p-azaquinodimethane moieties has been designed and synthesized. • Pi-extented aromatic-quinoidal systems have been prepared. • Bottom-gate top-contact field-effect transistors show mobilities up to 0.12 cm2 V−1 s−1. [ABSTRACT FROM AUTHOR]

Novel conjugated donor-acceptor (D-A) type polymers (P1-P3) possessing thieno[3,2- b ]thiophenes (TT) as donors having different functional groups and 2,1,3-benzothiadiazole (BT) as an acceptor were designed and synthesized via palladium-catalyzed Sonogashira coupling reaction. Their electronic and optical properties were investigated by UV–Vis and fluorescence spectroscopies and cylic voltammetry analysis. Organic field-effect transistor (OFET) of the polymers were fabricated using biodegradable and environmental-friendly khaya gum as a high dielectric layer to investigate their charge transport characteristics were at low voltage. All the polymers displayed a p-type field-effect behaviour, among which alkyl chain (C 9 H 19) substituted P2 exhibited the highest average saturated hole mobility, μ sat , 0.086 cm2 V−1 s−1, on/off current ratio, I on /I off = 1.0 × 103, and subthreshold swing, SS, 425 mV dec−1. The results presented in this work corroborate that the three novel TT-BT polymers have promising potential for electronic and optoelectronic applications, in particular, where tunability of the field-effect behaviour is essential for performance. [Display omitted] • Thienothiophene and benzothiadiazole based D-A polymers containing various functional groups. • Effects of different functional groups (4-CNPh, C 9 H 19 , Ph) on device performance. • A high OFET performance with maximum hole mobility of μ sat , 0.086 cm2/Vs. [ABSTRACT FROM AUTHOR]

Organic field-effect transistor (OFET)-based sensors have gained considerable attention for information perception and processing in developing artificial intelligent systems owing to their amplification function and multiterminal regulation. Over the last few decades, extensive research has been conducted on developing OFETs with steep subthreshold swings (SS) to achieve high-performance sensing. In this review, based on an analysis of the critical factors that are unfavorable for a steep SS in OFETs, the corresponding representative strategies for achieving steep SS are summarized, and the advantages and limitations of these strategies are comprehensively discussed. Furthermore, a bridge between SS and OFET sensor performance is established. Subsequently, the applications of OFETs with steep SS in sensor systems, including pressure sensors, photosensors, biochemical sensors, and electrophysiological signal sensors. Lastly, the challenges faced in developing OFET sensors with steep SS are discussed. This study provides insights into the design and application of high-performance OFET sensor systems., (© 2024 Wiley‐VCH GmbH.)

• Two new copper(II)-phthalocyanines have been successfully synthesized. • Compounds not aggregate into the solution. • Peripheral substituted copper(II)-phthalocyanines exhibit high on/off ratio. • Non-peripheral substituted copper(II)-phthalocyanines show high mobility. New two tetra-peripheral/non-peripheral substituted copper(II)-phthalocyanines have been synthesized and characterized by using ATR-IR, MALDI-TOF/MS and UV–Vis spectroscopy. The electrical characterization and conducting properties of copper(II)-phthalocyanine compounds have been achieved in order to determine their use as a semiconductor layer in organic field effect transistors (OFETs). The OFETs characterization has been performed and the tetra-peripheral/non-peripheral substituted copper(II)-phthalocyanines OFET carrier mobility of about 1.31×10−3 cm2/V.s and 1.42×10−3 cm2/V.s, respectively. On/off current ratio of ∼103 and ∼102; threshold voltage of (-30 V, -32 V), respectively were measured. [Display omitted] [ABSTRACT FROM AUTHOR]

Three polymers with general structure (D-A) n were designed and synthetized to investigate the interaction of strong donors and strong acceptors in polymer chain. They are based on different fused thiophenes (1Th : 4,4′-bis(2-ethylhexyl)-cyclopenta [2,1-b:3,4-b']dithiophene; 2Th : 4,8-bis [(2-ethylhexyl)oxy]benzo [1,2-b:4,5-b']dithiophene; 3Th : 4,8-bis(4-fluoro-5-(2-ethylhexyl)-thiophen-2-yl)benzo [1,2-b:4,5-b']bisthiophene) and N , N ′-bis(2-ethylhexyl)-1,8:4,5-naphthalenetetracarboxdiimide (NDI). Fused benzo- and cyclopenta-thiophene derivatives were selected because they are known for their strong electron-donating properties. NDI was coupled with them in polymer chain because it is one of the best known electron withdrawing units. Such combination of donor and acceptor units is one of the strategies for obtaining low band gap conjugated polymers with semiconducting properties for many applications. The interaction of donors and acceptors is a key factor determining the properties of such polymers. The electrochemical and spectroscopic measurement were supported by DFT calculations. Moreover, organic field effect transistors (OFET) were fabricated to demonstrate the feasibility of using the newly developed materials in electronic devices. [Display omitted] • Donor-acceptor polymers based on fused thiophene were characterized. • The results indicate complex relationships between structure and physicochemical properties. • Various properties of polymers influence the performance of OFETs. • Polydispersity and its multimodality are important factors influencing its electronic properties in solid state. [ABSTRACT FROM AUTHOR]

[Display omitted] • PBIST bearing swallowtails demonstrated stable room temperature columnar oblique phase, with low clearing point. • Solution processable, printable liquid crystalline PBIST showed n-type mobility of 0.008 cm2V-1s-1. • High solubility and fluorescence quantum yield makes PBIST an ideal candidate to explore its electroluminescence. • 0.5 wt% doping of PBIST in CBP yielded a high EQE of 7% and a luminescence of 1787 cd/m2 in a solution processed OLED. • The high EQE of PBIST attributed to its high charge carrier mobility and triplet –triplet annihilation (TTA) process. Synthesis of highly fluorescent compounds is currently a critical requirement to facilitate the economical and metal-independent manufacture of organic light-emitting diodes (OLEDs) on a large scale. This study presents a highly soluble, swallow tail based electron deficient perylene bisimide (PBIST) exhibiting room temperature columnar oblique (Col ob) liquid crystalline behavior along with a high photoluminescence quantum yield, positioning itself as a promising candidate for efficient OLEDs. Incorporation of swallow tails helped in enhancing the solubility and reduction of the clearing points. This unique tailor-made molecular design with the liquid crystalline phase allowed a demonstration of n-type field effect mobility of 0.008 cm2 V−1s−1 when annealed in the liquid crystalline mesophase range (at 70 °C) which can be exploited in the fabrication of printable electronic devices. Capitalizing on the high charge transport and luminescence attributes of PBIST , a series of devices were fabricated by utilizing PBIST as a single emitter and dispersed at different concentrations of 0.3, 0.5 and 1 wt% in host material CBP. Impressively, doped devices featuring the CBP as a host at a 0.5 wt% PBIST concentration exhibited an external quantum efficiency (EQE) as high as 7 %, accompanied by a luminance of 1787 cd/m2. The high EQE is attributed mainly to the triplet–triplet annihilation (TTA) process. This notable EQE enhancement signifies a substantial stride towards expanding the utility of multifunctional columnar self-assembled materials for the advancement of OLEDs. [ABSTRACT FROM AUTHOR]

[Display omitted] • New AZO-TZD derivatives (1–11) were synthesized using CSA as a catalyst. The compounds were studied by molecular docking. • A solvatochromic effects with electron-withdrawing and electron-donating substituent investigated. • Computational analysis of molecular geometry, optoelectronic properties, and ionization potential was conducted. • The role of different solvents, substituents, and the donor and acceptor properties of the synthesized compounds considered. • UV–visible spectrum analysis, shows acceptor–donor-acceptor characteristics resembling an organic field-effect transistor OFETs. Here, new AZO-TZD derivatives (1−11) were synthesized using cellulose sulphuric acid (CSA) as a catalyst to prepare diazonium salts and Knoevenagel condensation to produce final products. The prepared dyes were characterized by various methods including UV–Vis, FT-IR, MS, NMR spectroscopic techniques, X-ray diffraction analysis (XRD) and elemental analysis to perform detailed structure elucidation. Then, in another attempt, solvatochromic absorption was studied using different solvents. Also, the effects of substituent with electron-withdrawing and electron-donating groups at their o -, m -, and p -position were investigated. To access a deeper understanding of molecular properties, computational analysis of molecular geometry, optoelectronic properties, and ionization potential was performed. The purpose of the calculations is to clarify the role of different solvents, substituents and donor and acceptor characteristics of the connected rings in the synthesized compounds. Analysis of the UV–Vis spectrum confirmed that these molecules have acceptor–donor-acceptor characteristics that resemble an organic field effect transistor (OFET). In other efforts to evaluate their use as antibacterial, anticancer and anti-Alzheimer agents and their interaction with four different types of enzymes, such as carotenoid dehydrosqualene synthase (PDB ID: 3ACX, gram-positive), aromatase (PDB Id: 4GL7) and acetylcholinesterase (PDB) Id: 7AIX), through UDP-3-O-Acyl- N -Acetylglucosamine Deacetylase (PDB ID: 5U39, gram-negative) and their anticancer docking calculations were investigated. [ABSTRACT FROM AUTHOR]

Graphdiyne particles (GDYP), newcomers of carbon family, were employed as nano-floating gates in organic field-effect transistor (OFET) memories. The charge-trapping layer was prepared by blending GDYP into a polystyrene (PS) matrix. The effect of GDYP doping ratio on memory performances was investigated, and the OFET memory with the optimal doping concentration of the GDYP (0.3 mg/mL) exhibits ambipolar memory behavior with a wide memory window as large as 86 V, excellent retention time over 104 s with a high ON/OFF current ratio of 7.5 × 105. This work demonstrates that graphdiyne is a promising charge-trapping material for high-performance nonvolatile OFET memory devices. [Display omitted] • Graphdiyne particles were employed as nano-floating-gate materials for nonvolatile OFET memory. • The effect of graphdiyne particles doping ratio on memory performances was systematically investigated. • The as fabricated OFET exhibits bipolar memory behavior, memory window up to 86 V, retention time over 104 s with ON/OFF current ratio of 7.5 × 105. • Graphdiyne particle is a promising charge trapping material. [ABSTRACT FROM AUTHOR]

The magnetic alignment of molecules, which exploits the anisotropy of diamagnetic susceptibility, provides a clean and versatile approach to the structural manipulation of semiconducting polymers. Here, the magnetic-alignment dynamics of two molecular-weight ( M W ) batches of a diketopyrrolopyrrole (DPP)-based copolymer (PDVT-8) were investigated. Microstructural characterizations revealed that the magnetically aligned, high- M W ( M n = 53.7 kDa) PDVT-8 film exhibited a higher degree of backbone chain alignment and film crystallinity compared with the low- M W ( M n = 17.6 kDa) PDVT-8 film grown via the same magnetic alignment method. We found that as the M W increases, the degree of preaggregation of the polymer molecules in solution significantly increases and the aggregation mode changes from H-aggregation to J-aggregation through a cooperative assembly mechanism. These events improved the responsiveness of high- M W polymer molecules to magnetic fields. Field-effect transistors based on the magnetic aligned high- M W PDVT-8 films exhibited a 6.8-fold increase in hole mobility compared to the spin-coated films, along with a mobility anisotropy ratio of 12.6. This work establishes a significant correlation among chain aggregation behavior in solution, polymer film microstructures, magnetic responsiveness, and carrier transport performance in donor-acceptor polymer systems.

• Side-chain engineering tunes gas performance and mechanical properties. • Long side chains of P3AT reduce OFET performance. • P3DDT improved the sensibility due to the accessible penetration of gas molecules. • Long side chains of P3AT render film to be softer due to large free volume. Poly(3-alkylthiophene) (P3AT) is a representative p-type organic semiconductor with a distinctive molecular structure that incorporates a π-electron system, promoting charge carrier mobility and providing exceptional electrical conductivity. The alkyl side chain linked to the π-electron backbone was found to have a significant effect on charge carrier transport and mechanical properties. This study presents a comprehensive comparison of the gas-sensing performances of various gases (NO 2 , SO 2 , and CO 2) and the mechanical properties of gas sensors fabricated from P3AT with alkyl chain lengths of 6, 8, 10, and 12 (P3HT, P3OT, P3DT, and P3DDT). Our investigations revealed that as the alkyl side chain length increased, the gas sensor performance significantly improved owing to the increase in free volume, concurrently promoting improved flexibility. The P3DDT sensor exhibited a sensitivity approximately twice that of the P3HT sensor, along with superior mechanical flexibility owing to its free volume. [ABSTRACT FROM AUTHOR]

In this study, the morphology and electronic properties of semiconducting polymer films were investigated in relation to a different drying behavior induced by the spinning time variation. Morphology changes related to the decreased spinning time were evaluated for p-type (P3HT, PQT-12) and n-type (N2200, PDBPyBT) polymer films fabricated at different preparation conditions. Based on the improved morphology, OFET devices were fabricated showing a 2.5 times carrier mobility increase (0.044 ± 0.012 cm2V−1s−1 for 3 s spin to 0.018 ± 0.011 cm2V−1s−1 for 30 s spin) for P3HT films, and 3 times improvement (0.088 ± 0.023 cm2V−1s−1 for 50 s to 0.28 ± 0.017 cm2V−1s−1 for 5 s) for N2200 films. For short spinning times, the slow drying of residual solvent allowed for the self-organization of polymer chains improving the crystallinity of polymer films. The presented approach synergizes the benefits of the spin coating method, like highly controlled film uniformity and thickness, with improved film morphology provided by other methods, like drop casting, or dip-coating. [Display omitted] • Short spin coating time is beneficial for the improved morphology of thin films. • Slow drying is critical for self-organization of polymer chains in thin film. • Carrier mobility was notably increased with slower drying of the polymer solution. • Synergy of benefits of different thin film preparation methods is achieved. [ABSTRACT FROM AUTHOR]