MARVEL analysis of high-resolution rovibrational spectra of 16O12C18O.

Empirical rovibrational energy levels are presented for the third most abundant, asymmetric carbon dioxide isotopologue, 16O12C18O, based on a compiled dataset of experimental rovibrational transitions collected from the literature. The 52 literature sources utilized provide 19,438 measured lines with unique assignments in the wavenumber range of 2-12,676 cm-1. The MARVEL (Measured Active Rotational-Vibrational Energy Levels) protocol, which is built upon the theory of spectroscopic networks, validates the great majority of these transitions and outputs 8786 empirical rovibrational energy levels with an uncertainty estimation based on the experimental uncertainties of the transitions. Issues found in the literature data, such as misassignment of quantum numbers, typographical errors, and misidentifications, are fixed before including them in the final MARVEL dataset and analysis. Comparison of the empirical energy-level data of this study with those in the line lists CDSD-2019 and Ames-2021 shows good overall agreement, significantly better for CDSD-2019; some issues raised by these comparisons are discussed.

An Assessment of the Effects of Guanidinoacetic Acid on the Performance and Immune Response of Laying Hens Fed Diets with Three Levels of Metabolizable Energy.

Different levels of metabolizable energy (ME) and the inclusion of guanidinoacetic acid (GAA) in the diet of 53-week-old Lohmann LSL-CLASSIC hens were used to evaluate its effect on reproductive parameters, egg quality, intestinal morphology, and the immune response. Six diets were used in a 3 × 2 factorial design, with three levels of ME (2850, 2800, and 2750 kcal/kg), and with (0.08%) or without the inclusion of GAA. The addition of GAA to diets with low levels of ME increased (p < 0.05) egg production and egg mass. Moreover, hens fed with 2800 kcal/g without GAA had the highest concentration (p < 0.05) of serum interleukin IL-2, while those fed diets with the same amount of ME but supplemented with 0.08% GAA had the lowest concentration. Finally, the inclusion of 0.08% GAA increased (p < 0.05) the concentration of vascular endothelial growth factor (VEGF), regardless of the ME level in the diet. This study highlights the potential role of GAA in decreasing the energy level of ME (50-100 kcal/g) in the feeding of hens and in the modulation of specific immune responses. Further research is recommended to fully understand the mechanisms of action of GAA on the mechanism target of rapamycin and its relationship with the immune response.

Effects of dietary energy levels on microorganisms and short-chain fatty acids of rumen and tight junction proteins in Honghe Yellow cattle.

This study was conducted to investigate the effects of dietary energy levels on microorganisms and short-chain fatty acids (SCFAs) of rumen and the expression of tight junction proteins in Honghe Yellow cattle. A total of fifteen male Honghe Yellow cattle were randomly divided into three treatments (five replicates per treatment), consisting of formulated energy concentrations of 5.90 MJ/kg (high-energy diet, group H), 5.60 MJ/kg (medium-energy diet, group M) and 5.30 MJ/kg (low-energy diet, group L). The results showed that compared with group H, the expression of Claudin-1 in rumen epithelium of groups M and L was increased, but the expression of ZO-1 was decreased (p < 0.05). Moreover, compared with group H, group M down-regulated the expression of Occludin and Claudin-1 in the brain (p < 0.05). For rumen bacteria, the dominant phyla included Bacteroidetes and Firmicutes, the abundance of Actinobacteriota in groups M and L was significantly increased compared with group H (p < 0.05). At the genus level, the relative abundance of Corynebacterium, Eubacterium_nodatum_group and Neisseraceae in groups M and L was significantly decreased compared with group H (p < 0.05). For rumen fungi, the dominant phyla included Basidiomycota, Ascomycota and Neocariastigomycota, the relative abundance of Ascomycetes was significantly higher than that of groups M and L compared with group H (p < 0.05). At the genus level, the relative abundance of Neocelimastigaceae and Myceliophthora in groups M and L was significantly reduced compared with group H (p < 0.05). Furthermore, the expression of Claudin-1 in rumen epithelium was significantly positively correlated with Actinobacteriota, Corynebacterium and Neisseriaceae. The expression of ZO-1 in the spinal cord was significantly positively correlated with Myceliophthora. The expression of Occludin in brain was positively correlated with valerate content (p < 0.05). In summary, dietary energy levels affected the rumen microbiota of Honghe Yellow cattle. The expression of Claudin-1 in rumen epithelium and the total SCFAs concentration were increased with decreasing dietary energy levels, but the expression of Claudin-1 in brain and ZO-1 in the spinal cord were reduced with decreasing dietary energy levels. Meanwhile, the rumen microbiota and SCFAs were significantly correlated with the expression of TJP.

Key Roles of Interfaces in Inverted Metal-Halide Perovskite Solar Cells.

Metal-halide perovskite solar cells (PSCs), an emerging technology for transforming solar energy into a clean source of electricity, have reached efficiency levels comparable to those of commercial silicon cells. Compared with other types of PSCs, inverted perovskite solar cells (IPSCs) have shown promise with regard to commercialization due to their facile fabrication and excellent optoelectronic properties. The interlayer interfaces play an important role in the performance of perovskite cells, not only affecting charge transfer and transport, but also acting as a barrier against oxygen and moisture permeation. Herein, we describe and summarize the last three years of studies that summarize the advantages of interface engineering-based advances for the commercialization of IPSCs. This review includes a brief introduction of the structure and working principle of IPSCs, and analyzes how interfaces affect the performance of IPSC devices from the perspective of photovoltaic performance and device lifetime. In addition, a comprehensive summary of various interface engineering approaches to solving these problems and challenges in IPSCs, including the use of interlayers, interface modification, defect passivation, and others, is summarized. Moreover, based upon current developments and breakthroughs, fundamental and engineering perspectives on future commercialization pathways are provided for the innovation and design of next-generation IPSCs.

Enhancing Strategy of the Small-Polaron Conductivity in LaCrO3: First-Principles Calculations and Experimental Validation.

LaCrO3 (LCO) has promising applications as a p-type conductive material in the fields of transparent conducting oxes, high-temperature sensors, and magnetohydrodynamic power generators. However, the easy volatility of the Cr element, along with the issues of low electrical conductivity caused by the small-polaron conduction mechanism and wide band gap, has hindered the widespread application of LCO. In this work, based on band engineering and defect engineering, we screened doping schemes through first-principles calculations that can reduce Cr volatility by enhancing the Cr-O bond energy. We also aimed to promote small-polaron hopping and improve the electrical conductivity by introducing impurity levels. Additionally, we conducted a thorough analysis of the small-polaron conductivity mechanism. Through the solid-state method, we successfully prepared codoped LCO with Ca and Zn. The Zn dopants effectively enhanced the Cr-O bond strength, suppressed the Cr volatility, and improved high-temperature stability. The Zn dopants introduced additional impurity energy levels within the band gap, significantly changing the mobility of small polarons. Through optimal doping concentration, the La0.7Ca0.3Cr0.95Zn0.05O3 sample demonstrated a significant enhancement in electrical conductivity compared to La0.7Ca0.3CrO3, increasing from 7 to 60 at 1000 K. Additionally, the impurity energy levels enhanced the asymmetry near the Fermi level, resulting in an increased Seebeck coefficient (S). This is beneficial for the production of high-temperature sensors. The output voltage of an LCO thermocouple module reaches up to 58 mV at 2170 K, indicating that the performance optimization strategy employed in this work has significant implications for the regulation and application of oxide electrical materials.

Robust Dipolar Layers between Organic Semiconductors and Silver for Energy-Level Alignment.

The interface between a metal electrode and an organic semiconductor (OS) layer has a defining role in the properties of the resulting device. To obtain the desired performance, interlayers are introduced to modify the adhesion and growth of OS and enhance the efficiency of charge transport through the interface. However, the employed interlayers face common challenges, including a lack of electric dipoles to tune the mutual position of energy levels, being too thick for efficient electronic transport, or being prone to intermixing with subsequently deposited OS layers. Here, we show that monolayers of 1,3,5-tris(4-carboxyphenyl)benzene (BTB) with fully deprotonated carboxyl groups on silver substrates form a compact layer resistant to intermixing while capable of mediating energy-level alignment and showing a large insensitivity to substrate termination. Employing a combination of surface-sensitive techniques, i.e., low-energy electron microscopy and diffraction, X-ray photoelectron spectroscopy, and scanning tunneling microscopy, we have comprehensively characterized the compact layer and proven its robustness against mixing with the subsequently deposited organic semiconductor layer. Density functional theory calculations show that the robustness arises from a strong interaction of carboxylate groups with the Ag surface, and thus, the BTB in the first layer is energetically favored. Synchrotron radiation photoelectron spectroscopy shows that this layer displays considerable electrical dipoles that can be utilized for work function engineering and electronic alignment of molecular frontier orbitals with respect to the substrate Fermi level. Our work thus provides a widely applicable molecular interlayer and general insights necessary for engineering of charge injection layers for efficient organic electronics.

The infrared absorption spectrum of radioactive water isotopologue H215O.

A room temperature line list for the H215O radioactive isotopologue of the water molecule is computed using the variational nuclear-motion DVR3D program suite and an empirical high-precision potential energy function. The line list consists of rotation-vibrational energies and Einstein-A coefficients, covering a wide spectral range from 0 to 25000 cm-1 and the total angular momenta J up to 30. Estimates of air-broadening coefficients are provided. Experimentally derived energies of H216O, H217O and H218O from the literature are used to provide improved energies for important states with uncertainty estimates for the H215O. A number of the wmost promising spectroscopic ranges for the detection of H215O are proposed. The calculated absorption spectrum should be useful for the study gaseous radioactive water at IR region, determining concentration, etc.

COF/In2S3 S-Scheme Photocatalyst with Enhanced Light Absorption and H2O2-Production Activity and fs-TA Investigation.

Photocatalytic hydrogen peroxide (H2O2) synthesis from water and O2 is an economical, eco-friendly, and sustainable route for H2O2 production. However, single-component photocatalysts are subjected to limited light-harvesting range, fast carrier recombination, and weak redox power. To promote photogenerated carrier separation and enhance redox abilities, an organic/inorganic S-scheme photocatalyst is fabricated by in situ growing In2S3 nanosheets on a covalent organic framwork (COF) substrate for efficient H2O2 production in pure water. Interestingly, compared to unitary COF and In2S3, the COF/In2S3 S-scheme photocatalysts exhibit significantly larger light-harvesting range and stronger visible-light absorption. Partial density of state calculation, X-ray photoelectron spectroscopy, and femtosecond transient absorption spectroscopy reveal that the coordination between In2S3 and COF induces the formation of mid-gap hybrid energy levels, leading to smaller energy gaps and broadened absorption. Combining electron spin resonance spectroscopy, radical-trapping experiments, and isotope labeling experiments, three pathways for H2O2 formation are identified. Benefited from expanded light-absorption range, enhanced carrier separation, strong redox power, and multichannel H2O2 formation, the optimal composite shows an impressive H2O2-production rate of 5713.2 µmol g-1 h-1 in pure water. This work exemplifies an effective strategy to ameliorate COF-based photocatalysts by building S-scheme heterojunctions and provides molecular-level insights into their impact on energy level modulation.

Data Cleansing and Sub-Unit-Based Molecular Description Enable Accurate Prediction of The Energy Levels of Non-Fullerene Acceptors Used in Organic Solar Cells.

Non-fullerene acceptors (NFAs) have recently emerged as pivotal materials for enhancing the efficiency of organic solar cells (OSCs). To further advance OSC efficiency, precise control over the energy levels of NFAs is imperative, necessitating the development of a robust computational method for accurate energy level predictions. Unfortunately, conventional computational techniques often yield relatively large errors, typically ranging from 0.2 to 0.5 electronvolts (eV), when predicting energy levels. In this study, the authors present a novel method that not only expedites energy level predictions but also significantly improves accuracy , reducing the error margin to 0.06 eV. The method comprises two essential components. The first component involves data cleansing, which systematically eliminates problematic experimental data and thereby minimizes input data errors. The second component introduces a molecular description method based on the electronic properties of the sub-units comprising NFAs. The approach simplifies the intricacies of molecular computation and demonstrates markedly enhanced prediction performance compared to the conventional density functional theory (DFT) method. Our methodology will expedite research in the field of NFAs, serving as a catalyst for the development of similar computational approaches to address challenges in other areas of material science and molecular research.

MARVEL analysis of high-resolution rovibrational spectra of 13 C 16 O 2 .

A set of empirical rovibrational energy levels, obtained through the MARVEL (measured active rotational-vibrational energy levels) procedure, is presented for the 13 C 16 O 2 isotopologue of carbon dioxide. This procedure begins with the collection and analysis of experimental rovibrational transitions from the literature, allowing for a comprehensive review of the literature on the high-resolution spectroscopy of 13 C 16 O 2 , which is also presented. A total of 60 sources out of more than 750 checked provided 14,101 uniquely measured and assigned rovibrational transitions in the wavenumber range of 579-13,735 cm - 1 . This is followed by a weighted least-squares refinement yielding the energy levels of the states involved in the measured transitions. Altogether 6318 empirical rovibrational energies have been determined for 13 C 16 O 2 . Finally, estimates have been given for the uncertainties of the empirical energies, based on the experimental uncertainties of the transitions. The detailed analysis of the lines and the spectroscopic network built from them, as well as the uncertainty estimates, all serve to pinpoint possible errors in the experimental data, such as typos, misassignment of quantum numbers, and misidentifications. Errors found in the literature data were corrected before including them in the final MARVEL dataset and analysis.

Synthesis, Properties, and Application of Ultrathin and Flexible Tellurium Nanorope Films: Beyond Conventional 2D Materials.

Nanomaterials that can be easily processed into thin films are highly desirable for their wide range of applicability in electrical and optical devices. Currently, Te-based 2D materials are of interest because of their superior electrical properties compared to transition metal dichalcogenide materials. However, the large-scale manufacturing of these materials is challenging, impeding their commercialization. This paper reports on ultrathin, large-scale, and highly flexible Te and Te-metal nanorope films grown via low-power radiofrequency sputtering for a short period at 25 °C. Additionally, the feasibility of such films as transistor channels and flexible transparent conductive electrodes is discussed. A 20 nm thick Te-Ni-nanorope-channel-based transistor exhibits a high mobility (≈450 cm2 V-1 s-1 ) and on/off ratio (105 ), while 7 nm thick Te-W nanorope electrodes exhibit an extremely low haze (1.7%) and sheet resistance (30 Ω sq-1 ), and high transmittance (86.4%), work function (≈4.9 eV), and flexibility. Blue organic light-emitting diodes with 7 nm Te-W anodes exhibit significantly higher external quantum efficiencies (15.7%), lower turn-on voltages (3.2 V), and higher and more uniform viewing angles than indium-tin-oxide-based devices. The excellent mechanical flexibility and easy coating capability offered by Te nanoropes demonstrate their superiority over conventional nanomaterials and provide an effective outlet for multifunctional devices.

Buried Interface Optimization for Flexible Perovskite Solar Cells with High Efficiency and Mechanical Stability.

The power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs) are significantly reduced by defect-induced charge non-radiative recombination. Also, unexpected residual strain in perovskite films leads to an unfavorable impact on the stability and efficiency of PSCs, notably flexible PSCs (f-PSCs). Considering these problems, a thorough and effective strategy is proposed by incorporating phytic acid (PA) into SnO2 as an electron transport layer (ETL). With the addition of PA, the Sn inherent dangling bonds are passivated effectively and thus enhance the conductivity and electron mobility of SnO2 ETL. Meanwhile, the crystallization quality of perovskite is increased largely. Therefore, the interface/bulk defects are reduced. Besides, the residual strain of perovskite film is significantly reduced and the energy level alignment at the SnO2 /perovskite interface becomes more matched. As a result, the champion f-PSC obtains a PCE of 21.08% and rigid PSC obtains a PCE of 21.82%, obviously surpassing the PCE of 18.82% and 19.66% of the corresponding control devices. Notably, the optimized f-PSCs exhibit outstanding mechanical durability, after 5000 cycles of bending with a 5 mm bending radius, the SnO2 -PA-based device preserves 80% of the initial PCE, while the SnO2 -based device only remains 49% of the initial value.

Energy eigenvalues and finite-temperature magnetization for the improved Scarf II potential in the presence of external magnetic and Aharonov-Bohm flux fields.

In this paper, the bound state solutions of the radial Schrödinger equation are obtained in closed form under an improved Scarf II potential energy function (ISPEF) constrained by external magnetic and Aharonov-Bohm (AB) flux fields. By constructing a suitable Pekeris-like approximation scheme for the centrifugal barrier, approximate analytical expressions for the bound-states and thermal partition function were obtained. With the aid of the partition function, an explicit equation for magnetization at finite temperatures is developed. The obtained equations were then applied to calculate the energy levels and magnetic properties of 7Li2 (2 3Πg), K2 (X 1Σg+), Mg2 (X 1Σg+) and NaBr (X 1Σ+) diatomic molecules. The obtained numerical results of the vibrational energies for these molecules were found to be in good agreement with theoretic and experimental values reported in the existing literature. The results indicated that by turning off the magnetic and AB fields, the energy levels of the diatomic molecules degenerate. The results further revealed that an increase in the temperature of the molecules and the AB field strengths leads to a linear decrease in magnetization.

Effect of thiophene rings rigidity on dye-sensitized solar cell performance. Dithienothiophene versus terthiophene as π- donor moiety.

Solar cells are fabricated based on two new dyes. Dye acts as an additive to thin layer interface. The effect of the π-conjugated rigidity of the thiophene rings on the photovoltaic characteristics has been investigated. The structures of the dye 1 was based on dithieno [3,2-b:2',3'-d] thiophene-2-cyanoacrylic acid, while dye 2 was based on [2,2':5',2″-terthiophene]-5-cyanoacrylic acid and were confirmed by elemental analysis, mass spectrometry, 1H NMR and 13C NMR spectral data. The P3HT/dye 1/nc-TiO2 solar cell produced the highest efficiency of 0.3 % with an open circuit voltage of 0.7 V compared to dye 2 solar cell. This has been attributed to the difference in energy levels of the dyes and location of their HOMO relative to conduction and valence bands of nc-TiO2. The dye 1 has rigid fused thiophene rings and its HOMO is located between valence band of TiO2 and HOMO of P3HT which leads to improve the charge carrier separation and increase the current density to reach 1.2 mA/cm2.

Effects of different energy levels and two levels of temperature-humidity indices on growth, blood metabolites, and stress biomarkers in Korean native calves.

This study investigated the effects of dietary energy levels on growth, blood metabolites, and stress biomarkers in Korean native calves subjected to heat stress (HS). Twenty-four calves (BW: 221.5 ± 24.9 kg; age: 162 ± 4.8 d) were randomly housed in climate-controlled chambers using 3 × 2 factorial design. There were three treatment groups including low energy (LE = 2.53), medium energy (ME = 2.63), and high energy levels (HE = 2.72 Mcal/kg of DM) and two stress levels (threshold: THI = 70-73; severe: THI = 89-91). The calves were adapted to 22 °C for 7 days, then to the target THI level for 14 days. Energy intake, average daily gain, and gain to feed ratio were determined to decline (p < 0.05) under severe HS compared with threshold. Under severe HS, rectal temperature was increased 0.67 °C compared with threshold. Severe HS increased glycine, ammonia, and 3-methylhistidine concentrations compared with threshold (p < 0.05). Gluconeogenic AAs in the blood were increased among the various energy levels regardless of HS. In PBMCs the expression of HSP70 gene was increased in the LE group (p < 0.05), and the HSP90 gene expression was increased in LE and ME groups (p < 0.05) under severe HS. However, the expression of genes HSP70 and HSP90 in HE group did not differ under severe HS (p > 0.05). It has been suggested that HE intake may have a beneficial effect on PBMCs by mitigating ATP depletion. No differences in growth performance were found when increasing energy intake with high protein (CP 17.5%) under HS. However, the increase in energy levels resulted in increased gluconeogenic AAs but decreased urea and 3-methylhistidine in blood. In conclusion, increased energy levels are thought to improve HS adaptability by inhibiting muscle degradation and glucose production using gluconeogenic AAs in Korea native calves under HS condition.

Measurement of the intensities of the long-range alpha particles from 212Po.

212Bi partially decays by ß- populating excited levels of 212Po. Some of these excited states of 212Po decay with very low probability by direct alpha-particle emissions instead of a gamma-alpha cascade. This effect was known since the earliest times after the discovery of radioactivity. Emission energies of these long-range alpha particles were measured in the past, but the activity ratios were not accurately determined. Relative intensities for these decays have now been experimentally determined. Results agree with data previously reported. It is the first time that an uncertainty estimate is provided for such experiment.

Analysis of experimental spectra of phosphine in the Tetradecad range near 2.3 µm using ab initio calculations.

Due to its major interest for the chemistry of planetary atmospheres and exobiology, accurate spectroscopy data of phosphine are required for the search of signatures of this molecule in astronomical observations. In this work, high resolution infrared laboratory spectra of phosphine were analyzed for the first time in the full Tetradecad region (3769-4763 cm-1) involving 26 rotationally resolved bands. Overall, 3242 lines were assigned in spectra previously recorded by Fourier transform spectroscopy at temperatures 200 K and 296 K, using a combined theoretical model based on ab initio calculations. The total nuclear motion Hamiltonian of PH3 including ab initio potential energy surface, was reduced to an effective Hamiltonian using the high-order contact transformation method adapted to vibrational polyads of the AB3 symmetric top molecules, followed by empirical optimization of the parameters. At this step, the experimental line positions were reproduced with a standard deviation of 0.0026 cm-1 that provided unambiguous identification of observed transitions. The effective dipole transition moments of the bands were obtained by fitting to the intensities obtained from variational calculations using the ab initio dipole moment surface. The assigned lines were used to newly determine 1609 experimental vibration-rotational levels up to Jmax = 18 with energy in the range 3896-6037 cm-1 that represents significant extension towards higher energies compared to previous works. Transitions for all 26 sublevels of the Tetradecad were identified but with noticeably fewer transitions for fourfold excited bands because of their weaker intensity. At the final step, pressure-broadened half widths were attached to each transition and a composite line list adopting ab initio intensities and empirical line positions corrected to the accuracy of about 0.001 cm-1 for strong and medium transitions was validated against experimental spectra available in the literature.

Interface Modification for Efficient and Stable Inverted Inorganic Perovskite Solar Cells.

Due to their excellent thermal stability and ideal bandgap, metal halide inorganic perovskite based solar cells (PSCs) with inverted structure are considered as an excellent choice for perovskite/silicon tandem solar cells. However, the power conversion efficiency (PCE) of inverted inorganic perovskite solar cells (PSCs) still lags far behind that of conventional n-i-p PSCs due to interfacial energy level mismatch and high nonradiative charge recombination. Herein, the performance of inverted PSCs is significantly improved by interfacial engineering of CsPbI3- x Brx films with 2-mercapto-1-methylimidazole (MMI). It is found that the mercapto group can preferably react with the undercoordinated Pb2+ from perovskite by forming Pb-S bonds, which appreciably reduces the surface trap density. Moreover, MMI modification results in a better energy level alignment with the electron-transporting material, promoting carrier transfer and reducing voltage deficit. The above combination results in an open-circuit voltage enhancement by 120 mV, yielding a champion PCE of 20.6% for 0.09 cm2 area and 17.3% for 1 cm2 area. Furthermore, the ambient, operational and heat stabilities of inorganic PSCs with MMI modification are also greatly improved. The work demonstrates a simple but effective approach for fabricating highly efficient and stable inverted inorganic PSCs.

Control of Bandgaps and Energy Levels in Water-Soluble Discontinuously Conjugated Polymers through Chemical Modification.

Bandgap and energy levels are crucial for developing new electronic and photonic devices because photoabsorption is highly dependent on the bandgap. Moreover, the transfer of electrons and holes between different materials depends on their respective bandgaps and energy levels. In this study, we demonstrate the preparation of a series of water-soluble discontinuously π-conjugated polymers through the addition-condensation polymerization of pyrrole (Pyr), 1,2,3-trihydroxybenzene (THB) or 2,6-dihydroxytoluene (DHT), and aldehydes, including benzaldehyde-2-sulfonic acid sodium salt (BS) and 2,4,6-trihydroxybenzaldehyde (THBA). To control the energy levels of the polymers, varying amounts of phenols (THB or DHT) were introduced to alter the electronic properties of the polymer structure. The introduction of THB or DHT into the main chain results in discontinuous conjugation and enables the control of both the energy level and bandgap. Chemical modification (acetoxylation of phenols) of the polymers was employed to further tune the energy levels. The optical and electrochemical properties of the polymers were also investigated. The bandgaps of the polymers were controlled in the range of 0.5-1.95 eV, and their energy levels could also be effectively tuned.

Deciphering the Effects of Molecular Dipole Moments on the Photovoltaic Performance of Organic Solar Cells.

The dielectronic constant of organic semiconductor materials is directly related to its molecule dipole moment, which can be used to guide the design of high-performance organic photovoltaic materials. Herein, two isomeric small molecule acceptors, ANDT-2F and CNDT-2F, are designed and synthesized by using the electron localization effect of alkoxy in different positions of naphthalene. It is found that the axisymmetric ANDT-2F exhibits a larger dipole moment, which can improve exciton dissociation and charge generation efficiencies due to the strong intramolecular charge transfer effect, resulting in the higher photovoltaic performance of devices. Moreover, PBDB-T:ANDT-2F blend film exhibits larger and more balanced hole and electron mobility as well as nanoscale phase separation due to the favorable miscibility. As a result, the optimized device based on axisymmetric ANDT-2F shows a JSC of 21.30 mA cm-2 , an FF of 66.21%, and a power conversion energy of 12.13%, higher than that of centrosymmetric CNDT-2F-based device. This work provides important implications for designing and synthesizing efficient organic photovoltaic materials by tuning their dipole moment.