Molecular Orbital Energy Levels Research Articles

Conjugated Group Tuning of Self‐Assembled Monolayer for Efficient Hole‐Transport Layer in Organic Solar Cells

AbstractP‐type carbazole‐derived self‐assembled monolayers (SAMs) have garnered significant attention as promising hole transport layers (HTLs) in the development of highly efficient organic solar cells (OSCs). However, it still lacks the effective navigation to modulate the terminal functional groups of SAMs to achieve a compromise between the highest occupied molecular orbital (HOMO) energy levels and self‐aggregation behavior. Herein, the terminal functional groups are adjusted and three SAMs are synthesized, namely, t‐Bu‐3PACz, Ph‐3PACz, and Bz‐3PACz to comprehensively investigate their intrinsic properties and influence on photovoltaic performance. Among them, Ph‐3PACz featuring an exceptionally suitable conjugated region and steric hindrance exhibits the best compatibility with the active layer, superior electrical conductivity, HOMO energy level aligning with polymer donor, and ordered film packing. As a result, the photovoltaic devices based on Ph‐3PACz exhibit an open‐circuit voltage (VOC) of 0.850 V, a short‐circuit current density (JSC) of 28.7 mA cm−2, and a fill factor (FF) of 78.5%, thus resulting in a remarkable power conversion efficiency (PCE) of 19.2%. This work provides an effective and easily navigable method to modulate the molecular packing and energy levels of SAMs, thereby achieving highly efficient OSCs.

Efficient All‐Polymer Solar Cells Enabled by a Novel Medium Bandgap Guest Acceptor

Comprehensive SummaryNear‐infrared (NIR)‐absorbing polymerized small molecule acceptors (PSMAs) based on a Y‐series backbone (such as PY‐IT) have been widely developed to fabricate efficient all‐polymer solar cells (all‐PSCs). However, medium‐bandgap PSMAs are often overlooked, while they as the third component can be expected to boost power conversion efficiencies (PCEs) of all‐PSCs, mainly due to their up‐shifted lowest unoccupied molecular orbital (LUMO) energy level, complimentary absorption, and diverse intermolecular interaction compared to the NIR‐absorbing host acceptor. Herein, an IDIC‐series medium‐bandgap PSMA (P‐ITTC) is developed and introduced as the third component into D18/PY‐IT host, which can not only form complementary absorption and cascade energy level, but also finely optimize active layer morphology. Therefore, compared to the D18/PY‐IT based parental all‐PSCs, the ternary all‐PSCs based on D18/PY‐IT:P‐ITTC obtain an increased exciton dissociation, charge transport, carrier lifetime, as well as suppressed charge recombination and energy loss. As a result, the ternary all‐PSCs achieve a high PCE of 17.64% with a photovoltage of 0.96 V, both of which are among the top values in layer‐by‐layer typed all‐PSCs. This work provides a method for the design and selection of the medium‐bandgap third component to fabricate efficient all‐PSCs.

Fabrication of high-efficiency perovskite solar cells using benzodithiophene-based random copolymeric hole transport material

The design of donor-acceptor (D-A)-based random copolymers-type hole transporting materials (HTMs) are important for achieving superior performance of perovskite solar cells (PSCs) with high durability. In this work, a 2-alkylthienyl-substituted benzodithiophene (BDTT)-based random copolymer (denoted as RCP-BDTTPD), containing 2-ethylhexylthiophene-substituted benzo[1,2-b:4,5-b′]dithiophene (BDTT as an electron-donor; M1) and two different side-chain functionalized thieno[3,4-c]-pyrrole-4,6‑dione as the electron-acceptors (M2 and M3), is prepared and applied as an efficient interfacial HTM for PSCs. The optical, electrochemical, and electronic properties of RCP-BDTTPD are shown to be structurally and energetically viable to serve as HTM for PSCs. The RCP-BDTTPD has deeper highest occupied molecular orbitals (HOMO; −5.53 eV) and lowest unoccupied molecular orbitals (LUMO; −3.57 eV) energy levels. This is shown to be energetically suitable for realizing better compatibility with Cs-containing formamidinium/methylammonium (FAMA) mixed-cation perovskite as light absorber having HOMO energy level (−5.85 eV). The RCP-BDTTPD possessing gradient band alignment with perovskite, which is shown to be highly significant for the extraction of charge carriers, resulting in higher hole mobility of PSCs. RCP-BDTTPD delivered a reasonably good Voc of 1.10 V and higher Jsc of 19.01 mAcm−2 and, champion power conversion efficiency (PCE) up to 15.30 % with hole mobility (1.34×10−3 cm2V−1s−1) and high durability (Encapsulated cell retention of its PCE about 98 % over 16 h under harsh environment: Temp. ∼85 °C, RH∼85 %). This work demonstrating a potential application of RCP-BDTTPD based HTMs for the fabrication of high-performance PSCs with high durability as well as low cost.

Naphthalene-Arylamine Starburst Architectures: Novel Hole Transport Materials for Enhanced OLED Performance

The excellent hole transfer material (HTM) is beneficial to improve the stability of the device, reduce turn-on voltage(Von) and make full use of the potential performance of the developed emissive materials. In this work, we designed and synthesized four HTMs with triarylamine and naphthalene compounds - SHT1- SHT4. The characteristics of these four compounds were investigated by TGA, DSC. UV–vis absorption and photoluminescence spectra. These four HTMs all exhibit excellent hole transmission capability for their high triplet energy levels (ET), outstanding thermal property, morphological stabilities and appropriate highest occupied molecular orbital (HOMO) energy levels with emissive layer (EML). Four top-emission blue OLEDs with SHT1 - SHT4 as hole transport layer (HTL) were fabricated and show good electroluminescence (EL) property. The results show that the device incorporating SHT3 exhibit the best device performances with a low Von of 2.79 V, external quantum efficiency (EQEmax) of 19.7 %, highest current efficiency (CEmax) and highest Power efficiency (PEmax) of 8.86 cd A-1 and 9.05 lm W-1, respectively.

Molecular design of furanoacene-based singlet fission sensitizers combining diradical character and cross-substitution

Singlet fission (SF) suffers from the scarcity of available SF chromophores and sensitizers. Tetracene, pentacene and their derivatives, are two typical model systems for the study of SF photophysical phenomena. Herein, the analogues of polyacenes, furanoacenes and their derivatives, were evaluated as potential SF chromophores and sensitizers through a theoretical study. The primary photostability were evaluated by the frontier molecular orbital energy levels, diradical characters and SF relevant excited state energies according to the type-I and −II photodegradation mechanisms. The cross-substitutions by combining central substitutions with triple bonds and terminal substituents enhance photostability, tune the SF relevant excited states efficiently, and give more appropriate E(T1) to be SF sensitizers. This work helps to give better understanding of the electronic structures and SF capability of furanoacenes.

Isomeric Dimer Acceptors for Stable Organic Solar Cells with over 19 % Efficiency

AbstractThe strategy of isomerization is known for its simple yet effective role in optimizing molecular configuration and enhancing the power conversion efficiency (PCE) of organic solar cells (OSCs). However, the impact of isomerization on the design of dimer acceptors has been rarely investigated, and the relationship between the chemical structure and optoelectronic property remains unclear. In this study, we designed and synthesized two dimer acceptor isomers named D‐TPh and D‐TN, which differ in the positional arrangement of their end capping groups. Compared to D‐TN, D‐TPh exhibited enhanced backbone planarity, elevated lowest unoccupied molecular orbital energy level, and more ordered molecular stacking. Consequently, the OSC device based on PM6 : D‐TPh achieved a PCE of 19.05 %, higher than that (PCE=18.42 %) of the device based on PM6 : D‐TN. Large‐area PM6 : D‐TPh devices (1 cm2) yielded a PCE of 18.00 %. More importantly, the extrapolated T80 lifetime of the PM6 : D‐TPh device is over 2800 h with MPP tracking under continuous one‐sun illumination. These results suggest that isomerization strategy is an effective way to optimize the molecular configuration of dimer acceptors for the fabrication of high‐efficiency and stable OSCs.

Ultra‐Low Threshold Voltage in N‐Type Organic Electrochemical Transistors Enabled by Organic Mixed Ionic‐Electronic Conductors with Dual Electron‐Withdrawing Substitutions

AbstractAchieving low threshold voltage (Vth) in organic electrochemical transistors (OECTs) is essential for minimizing power consumption and enhancing sensitivity in bioelectronic devices. However, obtaining OECT materials with ultra‐low Vth, close to 0 V for n‐type conjugated polymers remains challenging. Here, a conjugated polymer FBDOPV‐CNTVT is introduced, which features a rigid backbone structure and high electron deficiency, leading to an exceptionally low lowest unoccupied molecular orbital (LUMO) energy level of −4.67 eV, achieved through dual electron‐withdrawing substitutions. With its ultra‐low LUMO energy level, FBDOPV‐CNTVT exhibits high susceptibility to electrochemical doping, even demonstrating efficient doping near 0 V. Consequently, the OECT device employing FBDOPV‐CNTVT as the active material shows an ultra‐low Vth of 7.5 mV, setting a new record for the Vth of n‐type OECT devices. Furthermore, FBDOPV‐CNTVT exhibits a µC* value of 6.13 F cm−1 V−1 s−1 and retains ≈85% of its current after 2000 s cycling. This study highlights the potential of conjugated polymers with dual electron‐withdrawing substitutions to achieve ultra‐low LUMO energy levels, effectively reducing the Vth of n‐type OECT devices and promising advancements in bioelectronics.

The Fabrication of Polyimide-Based Tunable Charge Traps Ternary Memristors Doped with Ni-Co Coated Carbon Composite Nanofibers.

In the dynamic fields of information science and electronic technology, there is a notable trend towards leveraging carbon materials, favored for their ease of synthesis, biocompatibility, and abundance. This trend is particularly evident in the development of memristors, benefiting from the unique electronic properties of carbon to enhance device performance. This study utilizes sensitized chemical evaporation and spin-coating carbonization techniques to fabricate nickel-cobalt coated carbon composite nanofibers (SC-NCMNTs). Novel polyimide (PI) matrix composite memory devices were fabricated using in situ polymerization technology. Transmission electron microscopy (TEM) and micro-Raman spectroscopy analyses validated the presence of dual interface structures located between the Ni-Co-MWNTs, carbon composite nanofibers, and PI matrix, revealing a significant number of defects within the SC-NCMNTs/PI composite films. Consequently, this results in a tunable charge trap-based ternary resistive switching behavior of the composite memory devices, exhibiting a high ON/OFF current ratio of 104 and a retention time of 2500 s at an operating voltage of less than 3 V. The mechanism of resistive switching is thoroughly elucidated through a comprehensive charge transport model, incorporating molecular orbital energy levels. This study provides valuable insights for the rational design and fabrication of efficient memristors characterized by multilevel resistive switching states.

Designing a Highly Crystalline Polymer Donor with Alkylsilyl and Fluorine Substitution to Achieve Efficient Ternary Organic Solar Cells.

Adopting a ternary strategy is an effective approach to enhance the power conversion efficiency (PCE) in organic solar cells (OSCs). Previous research on highly efficient ternary systems has predominantly focused on those based on highly crystalline dual small molecule acceptors. However, limited attention has been given to ternary systems utilizing dual polymer donors. Herein, by incorporating the fluorine and alkylsilyl substitution, a new polymer donor named PX1 is developed, which demonstrates strong crystallinity and excellent miscibility with polymer PM6. Moreover, PX1 broadens and enhances the absorption properties of the PM6:L8-BO blends, and its molecular orbital energy level is situated between those of PM6 and L8-BO, highlighting its suitability as a third component. Introducing 20% PX1 into the PM6:L8-BO system resulted in a high PCE of 18.82%. PX1 effectively suppresses charge recombination and reduces energy losses, while also serving as a morphology modulator that enhances the crystallization and improves the molecular packing order of the active layer by shortening the π-π stacking distance and extending crystalline coherence length. These factors collectively contribute to the performance improvements in ternary devices. This study demonstrates that employing a dual polymer donor strategy is a promising approach for achieving high-performance ternary OSCs.

A Tricyclic Framework with Integrated B←N and Cyano Dual Functionalization for Superior n-Type Organic Electronics.

n-Type conjugated polymers featuring low-lying lowest unoccupied molecular orbital (LUMO) energy levels are essential for achieving high-performance n-type organic thin-film transistors (OTFTs) and organic thermoelectrics (OTEs). However, the synthesis of acceptors with strong electron-withdrawing characteristics presents a significant challenge. Herein, a peripheral functionalization strategy is employed on the widely used tricyclic framework anthracene by introducing dual N,O-bidentate BF2/B(CN)2 groups to enhance its electron-withdrawing capability. This approach successfully navigates synthetic challenges, leading to the development of two novel acceptor building blocks: DBNF and DBNCN. Compared to the counterparts with a single N,O-bidentate BF2/B(CN)2 moiety, DBNF and DBNCN exhibit an extended π-backbone, enhanced molecular packing, and improved electron-withdrawing properties. Utilizing these innovative acceptor monomers, copolymers, PDBNF and PDBNCN, are synthesized, which exhibit considerably suppressed LUMO ≈ -4.0 eV. The deep LUMO of PDBNF together with its favourable bimodal packing orientation leads to remarkable electron mobility of 3.04 cm² V⁻¹ s⁻¹ with improved stability in OTFTs. Importantly, efficient n-doping in OTEs is achieved with PDBNCN, exhibiting exceptional conductivity of 95.5 S cm⁻¹ and a maximum power factor of 147.8 μW m⁻¹ K⁻²-among the highest reported for solution-processed n-type polymers.

A Tricyclic Framework with Integrated B←N and Cyano Dual Functionalization for Superior n‐Type Organic Electronics

n‐Type conjugated polymers featuring low‐lying lowest unoccupied molecular orbital (LUMO) energy levels are essential for achieving high‐performance n‐type organic thin‐film transistors (OTFTs) and organic thermoelectrics (OTEs). However, the synthesis of acceptors with strong electron‐withdrawing characteristics presents a significant challenge. Herein, a peripheral functionalization strategy is employed on the widely used tricyclic framework anthracene by introducing dual N,O‐bidentate BF2/B(CN)2 groups to enhance its electron‐withdrawing capability. This approach successfully navigates synthetic challenges, leading to the development of two novel acceptor building blocks: DBNF and DBNCN. Compared to the counterparts with a single N,O‐bidentate BF2/B(CN)2 moiety, DBNF and DBNCN exhibit an extended π‐backbone, enhanced molecular packing, and improved electron‐withdrawing properties. Utilizing these innovative acceptor monomers, copolymers, PDBNF and PDBNCN, are synthesized, which exhibit considerably suppressed LUMO ≈ –4.0 eV. The deep LUMO of PDBNF together with its favourable bimodal packing orientation leads to remarkable electron mobility of 3.04 cm² V⁻¹ s⁻¹ with improved stability in OTFTs. Importantly, efficient n‐doping in OTEs is achieved with PDBNCN, exhibiting exceptional conductivity of 95.5 S cm⁻¹ and a maximum power factor of 147.8 μW m⁻¹ K⁻²—among the highest reported for solution‐processed n‐type polymers.

2D g-C3N5 p-Doping of Donor Material for High-Efficiency Organic Solar Cells.

Molecular doping of organic semiconductor is a great strategy for significantly regulating the electronic band structure of organic semiconductor while increasing charge mobility and carrier concentration. Here, a facile strategy is presented by introducing 2D g-C3N5 as a p-dopant into PM6, improving the charge mobility and hole carrier concentration of PM6. Moreover, the electron transfer between PM6 and g-C3N5 can effectively downshift the Fermi energy level and highest occupied molecular orbital (HOMO) energy level of PM6, which leads to the increase the built-in electric field of organic solar cells (OSCs). The addition of g-C3N5 also effectively enhances the crystallization of active layer, thereby improving the stability of OSCs. As a result, a champion bulk-heterojunction (BHJ) and layer-by-layer (LbL) structure OSCs are successfully achieved featuring a high-power conversion efficiency of 18.10%/18.25%, simultaneously having excellent device stability. This work shows that introducing a low concentration dopant into organic donor is an effective method for improving the electrical performance of organic donor and the efficiency of OSCs.

Dibenzothiophene S, S-Dioxide-Containing Dipolar Molecules As Efficient Hole-Transport Materials for p-i-n Perovskite Solar Cells.

Organic-inorganic hybrid perovskite solar cells (OIH-PSCs) have developed rapidly in the past decade, and the commercialization of OIH-PSCs demands low-cost hole-transport materials (HTMs) with high performance and stability. The present study synthesized two organic HTMs containing dibenzothiophene S-dioxide as the acceptor unit and triphenylamine as the donor (denoted by TPAF-SO2 and TPA-SO2). In TPAF-SO2, the methoxy group and adjacent fluorine atom were introduced to decrease the highest occupied molecular orbital energy level. In TPA-SO2, the methyl sulfide group is the end group that can passivate the lead ion. TPAF-SO2 and TPA-SO2 exhibit hole-transport mobilities as high as 1.12 × 10-3 and 2.31 × 10-3 cm2 v-1 s-1, respectively, and strongly passivate Pb vacancies. Compared with TPAF-SO2, TPA-SO2 is more suitable for the growth of perovskite crystals. The perovskite grown on the latter has a lower trap density and higher carrier mobility; thus, both the nonradiative recombination and the charge-transport loss are decreased. The OIH-PSC based on TPA-SO2 as the HTM achieved a power conversion efficiency (PCE) as high as 22.08%, whereas the device based on TPAF-SO2 achieved a PCE of only 18.42%. In addition, the unencapsulated device based on TPA-SO2 can maintain 85% of the initial PCE after being stored in N2 for 1200 h, whereas the device based on TPAF-SO2 decayed rapidly to zero in 800 h under the same conditions.

Exploring the activation potential of heme for 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol

The presence of chlorophenols in water poses a significant threat to human health and the environment. In response to this issue, a study was undertaken to evaluate the catalytic capabilities of chlorinated Heme towards common chlorophenols present in water, such as 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol. The study employed the B3LYP method, a sophisticated computational technique within density functional theory, to investigate the molecular interactions and transformations involved. It scrutinized structural parameters, Wiberg Bond Indices, which offer insights into the strength and nature of chemical bonds, along with spectroscopic data including infrared vibrational spectra, ultraviolet-visible absorption spectra, and molecular fluorescence spectra. Furthermore, the research analyzed molecular binding energies and orbital energy levels before and after the formation of complexes between Heme and the targeted chlorophenols. The findings indicate that Heme displays a notable activation characteristic towards these chlorophenols. This suggests that Heme could act as an effective catalyst in the degradation of chlorophenols in water, presenting a novel approach to water purification. The theoretical insights derived from this study are invaluable, potentially guiding the development of more efficient catalytic systems for treating chlorophenol-contaminated water, thereby reducing the environmental and health risks associated with these hazardous compounds.

Investigation of aluminum nitrate nanotube as the smart carriers for targeted delivery of gemcitabine anti-lung cancer drug

The potential of aluminum nitrate nanotube as a drug carrier for anti-lung cancer drug gemcitabine is examined based on the density functional theory (DFT) calculations. The adsorption geometries of gemcitabine drug onto the surface of nanotube are investigated for various orientation in order to attain the most stable configuration. Significant interaction is observed between the double bonded oxygen atom of the gemcitabine drug and aluminum atom of the nanocage. The charge transfer analysis indicates that there is significant interaction along with considerable charge transfer between gemcitabine and the aluminum nitrate nanotube. The electronic properties such as highest occupied molecular orbital, lowest unoccupied molecular orbitals energy levels, energy gap, chemical hardness, chemical potential, electrophilicity index, and dipole moment for the best three configurations of the complexation are examined. The recovery time calculations are also performed at 298.15 K temperature in order to study the drug desorption process on the targeted site. The stability of the complex is compared in both gas and aqueous medium. Eventually, this work interprets that aluminum nitrate nanotube can be considered to be suitable candidates for delivering gemcitabine anti-lung cancer drug in a biological system.

Design, synthesis, characterization, theoretical calculations, molecular docking studies, and biological evaluation of new Fe(II) and Cu(II) complexes of 2-acetylpyridine derivative sulfonyl hydrazone Schiff base

Sulfonylhydrazones and their metal complexes are known to have potential biological activity. In this study, new Fe(II) (1) and Cu(II) (2) complexes of the 2-acetylpyridine derivative sulfonyl hydrazone (LH) were prepared. The new metal complexes were characterized by elemental analysis, IR spectroscopy, UV spectroscopy, and magnetic moment measurements. The molecular structure of (2) was elucidated by X-ray diffraction analysis, and the crystal package was obtained in three-dimensional space. To support the intermolecular interactions obtained from the X-ray diffraction results, Hirshfeld surface analysis and two-dimensional fingerprint maps of (2) were generated. The optimized molecular structures, total energies, molecular orbital energy values, molecular electrostatic potential maps, percentage distributions of the atomic orbitals to the molecular orbital energy levels, and global reactivity parameters of LH, 1, and 2 are obtained by using DFT/B3LYP/6–311G(d, p) for LH and DFT/B3LYP/LanL2DZ for 1 and 2 is 1:2. Elemental analysis showed that the stoichiometric metal/ligand ratio for 1 and 2. All data indicate that the ligand coordinates with the metal atoms via pyridine imine /nitrogens and sulfonyl oxygen. The well-diffusion approach was also used to test the antibacterial properties of the ligand and complexes against harmful microbes. The compounds were tested for DNA cleavage using agarose gel electrophoresis. Complex 1 was found to be effective on the plasmid DNA of pBR322. Finally, molecular docking studies of LH, 1, and 2 with A-DNA (PDB ID:3V9D), and B-DNA (PDB ID:1BNA) were presented to compare the experimental and theoretical results.

Optimizing non-fullerene acceptor molecules constituting fluorene core for enhanced performance in organic solar cells: a theoretical methodology.

Looking for novel outstanding performance materials suitable for organic solar cells, we constructed a range of non-fullerene acceptors (NFAs) evolved from the recently synthesized acceptor molecule identified as DICTIF, structured around fluorene core where 2-(2,3-dihydro-3-oxo-1H-inden-1-ylidene) propanedinitrile presented the terminals end-groups. Employing density functional theory (DFT) and time dependent-DFT (TD-DFT) simulations, we have simulated the impact of altering the end groups of DICTIF molecule by five assorted acceptors molecules, for the purpose of exploring their opto-electronic properties and their performance in organic solar cell (OSC) applications. We proved that the designed non-fullerene acceptors provide enhanced efficiency compared to the synthesized molecule, such as planar geometries and narrower energy gap ranging from 1.51 to 1.95 eV. A red shift in absorption was observed for all tailored molecules (λmax = 583.5-711.4 nm) as compared to the reference molecule (λmax = 578 nm).Various decisive factors such as frontier molecular orbitals (FMOs), exciton binding energy (EB), absorption maximum (λmax), open circuit voltage (VOC), reorganization energies (RE), transition density matrix (TDM), reduced density gradient (RDG), and electron-hole overlap have also been computed for analyzing the performance of NFAs. Low reorganizational energy values facilitate charge mobility which improves the conductivity of all the designed molecules. This study showed that our novel tailored molecules might be suitable candidates for the fabrication of highly efficient photovoltaic materials. After testing various hybrid functionals, optimized geometries were assigned using DFT HSEH1PBE/6-31G(d) level of theory. Electronic excitations and absorption spectra were investigated using the TD-DFT MPW1PW91/6-31G(d) level of theory. We ascertained that HSEH1PBE/6-31G(d) level of theory yield the closest calculated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the DICTIF to the corresponding experimental ones and that TD-MPW1PW91//6-31G(d) was the most suitable level of theory for exploring electronic excitations and finding the maximum of absorption (λmax).

Theoretical Investigation on Carbazole Derivatives as Charge Carriers for Perovskite Solar Cell

The study explores carbazole‐based organic molecules as transport layers in durable perovskite solar cells, focusing on their optoelectronic and charge transfer properties. Thirteen carbazole derivatives are systematically analyzed via density functional theory (DFT) calculations to understand their structure and optoelectronic characteristics. Substituents like bromo, phenyl, thiophenyl, and pyridyl at positions 3,6‐ and 2,7‐ of carbazole were studied. Phenyl and thiophenyl substitutions lowered highest occupied molecular orbital (HOMO) energy levels, while bromo and pyridyl increased them, tuning HOMO energies from −5.45 to −6.03 eV. These energies align well with perovskite materials valence bands, with absorbance primarily below 400 nm, complementing perovskite absorption. The compounds showed high light‐harvesting efficiencies (LHEs) (0.22 to 0.94) and improved radiative lifetimes. Theoretical investigations identified most compounds as effective p‐type hole‐transport materials (HTM), except 3,6‐ and 2,7‐dithiophenyl carbazoles, which exhibited n‐type behavior due to low hole reorganization energies. Overall, the study highlights computational design's role in developing carbazole derivatives as promising charge carrier precursors for perovskite solar cells.

Regulating Molecular Structure of S,N‐Heteroacene Non‐fullerene Acceptors to Achieve Efficient Photoelectric Properties†

Comprehensive SummaryThe ternary strategy has demonstrated its efficacy in improving charge transport in organic solar cells (OSCs). Here, three novel non‐fullerene acceptors, SN6C9‐4F, SN6C9‐4Cl and SN6C10‐4F, based on S,N‐heteroacene linear backbone were designed and synthesized. The three acceptors exhibit excellent molecular coplanarity, high crystallinity and possess a deep‐lying lowest unoccupied molecular orbital energy level, which is beneficial for charge transport and injection in organic field‐effect transistors (OFETs). Notably, the OFET devices based on all three acceptors achieved impressive electron mobilities, with SN6C10‐4F achieving up to 0.73 cm2·V–1·s–1, which is one of the highest values among A‐D‐A type small molecules. In addition, the OSCs device based on PBDB‐T:SN6C9‐4F exhibited the best power conversion efficiency of 12.07% owing to its optimal morphology and enhanced charge transport. Moreover, the incorporation of SN6C9‐4F into the efficient PM6:L8‐BO binary system to form ternary OSCs resulted in extended absorption range, enhanced donor crystallization, improved and more balanced charge transport, ultimately leading to an improvement of PCE from 17.78% to 18.32%. This study highlights the potential of developing acceptors with distinct structures from Y‐series acceptors to broaden absorption and regulate donor crystallization, providing a novel approach to enhance the PCE of OSCs.

Synthesis, Stable Radical Anion and Energy Storage Performance of Pentacene Tetraimides

Imide functionalization has been widely proved to be an effective approach to enrich optoelectronic properties of polycyclic aromatic hydrocarbons (PAHs). However, appending multiple imide groups onto linear acenes is still a synthetic challenge. Herein, we demonstrate that by taking advantage of a “breaking and mending” strategy, a linear pentacene tetraimides (PeTI) was synthesized through a three‐step sequence started from the naphthalene diimides (NDI). Compared with the parent pentacene, PeTI shows a deeper‐lying lowest unoccupied molecular orbital (LUMO) energy level, narrower bandgap and better stability. The redox behavior of PeTI was firstly evaluated by generating a stable radical anion specie with the assistance of cobaltocene (CoCp2), and the structure of the electron transfer (ET) complex was confirmed by the X‐ray crystallography. Moreover, due to the presence of multiple redox‐active sites, we are able to show that the state‐of‐the‐art energy storage performance of the dealkylated PeTI (designated as PeTCTI) in organic potassium ion batteries (OPIBs) as an anode. Our results shed light on the application of multiple imides functionalized linear acenes, and the reported synthetic strategy provides an effective way to get access to longer nanoribbon imides with fascinating electronic properties.