RESUMEN
In organic solar cells (OSCs), electron acceptors have undergone multiple updates, from the initial fullerene derivatives, to the later acceptor-donor-acceptor type non-fullerene acceptors (NFAs), and now to Y-series NFAs, based on which efficiencies have reached over 19%. However, the key property responsible for further improved efficiency from molecular structure design is remained unclear. Herein, the material properties are comprehensively scanned by selecting PC71BM, IT-4F, and L8-BO as the representatives for different development stages of acceptors. For comparison, asymmetric acceptor of BTP-H5 with desired loosely bounded excitons is designed and synthesized. It's identified that the reduction of intrinsically exciton binding energy (Eb) and the enhancement of exciton delocalization capability act as the key roles in boosting the performance. Notably, 100 meV reduction in Eb has been observed from PC71BM to BTP-H5, correspondingly, electron-hole pair distance of BTP-H5 is almost two times over PC71BM. As a result, efficiency is improved from 40% of S-Q limit for PC71BM-based OSC to 60% for BTP-H5-based one, which achieves an efficiency of 19.07%, among the highest values for binary OSCs. This work reveals the confirmed function of exciton delocalization capability quantitatively in pushing the efficiency of OSCs, thus providing an enlightenment for future molecular design.
RESUMEN
Hyacinth bean [Lablab purpureus (L.) Sweet], a plant belonging to the leguminous family and traditionally used for medicinal purposes in China, is a valuable resource with a wide range of health benefits. This review examines the bioactive compounds, health-promoting properties and functional food potential of hyacinth bean, highlighting its role in protecting against metabolic diseases and the underlying molecular mechanisms. According to existing research, hyacinth bean contains a diverse array of bioactive compounds, Consumption of hyacinth beans and hyacinth bean-related processed food products, as well as their use in medicines, is associated with a variety of health benefits that are increasingly favoured by the scientific community. In light of these findings, we posit that hyacinth bean holds great promise for further research and food application. © 2024 Society of Chemical Industry.
RESUMEN
Iodination has unlocked new potentials in organic photovoltaics (OPVs). A newly designed and synthesized iodinated non-fullerene acceptor, BO-4I, showcases exceptional excitation delocalization property with the exciton diffusion length increased to 80â nm. The enhanced electron delocalization property is attributed to the larger atomic radius and electron orbit of the iodine atom, which facilitates the formation of intra-moiety excitations in the acceptor phase. This effectively circumvents the charge transfer state-related recombination mechanisms, leading to a substantial reduction in non-radiative energy loss (ΔEnr ). As a result, OPV cell based on PBDB-TF : BO-4I achieves an impressive efficiency of 18.9 % with a notable ΔEnr of 0.189â eV, markedly surpassing their fluorinated counterparts. This contribution highlights the pivotal role of iodination in reducing energy loss, thereby affirming its potential as a key strategy in the development of advanced next-generation OPV cells.
RESUMEN
Organic solar cells (OSCs) are still suffering from the low light utilization and unstable under ultraviolet irradiation. To tackle these challenges, we design and synthesize a non-fused acceptor based on 1-(2-butyloctyl)-1H-pyrrole as π-bridge unit, denoted as GS70, which serves as active layer in the front-cell for constructing tandem OSCs with a parallel configuration. Benefiting from the well-complementary absorption spectra with the rear-cell, GS70-based parallel tandem OSCs exhibit an improved photoelectron response over the range between 600-700â nm, yielding a high short-circuit current density of 28.4â mA cm-2. The improvement in light utilization translates to a power conversion efficiency of 19.4 %, the highest value among all parallel tandem OSCs. Notably, owing to the intrinsic stability of GS70, the manufactured parallel tandem OSCs retain 84.9 % of their initial PCE after continuous illumination for 1000â hours. Overall, this work offers novel insight into the molecular design of low-cost and stability non-fused acceptors, emphasizing the importance of adopting a parallel tandem configuration for achieving efficient light harvesting and improved photostability in OSCs.
RESUMEN
Innovative molecule design strategy holds promise for the development of next-generation acceptor materials for efficient organic solar cells with low non-radiative energy loss (ΔEnr). In this study, we designed and prepared three novel acceptors, namely BTP-Biso, BTP-Bme and BTP-B, with sterically structured triisopropylbenzene, trimethylbenzene and benzene as side chains inserted into the shoulder of the central core. The progressively enlarged steric hindrance from BTP-B to BTP-Bme and BTP-Biso induces suppressed intramolecular rotation and altered the molecule packing mode in their aggregation states, leading to significant changes in absorption spectra and energy levels. By regulating the intermolecular π-π interactions, BTP-Bme possesses relatively reduced non-radiative recombination rate and extended exciton diffusion lengths. The binary device based on PB2 : BTP-Bme exhibits an impressive power conversion efficiency (PCE) of 18.5 % with a low ΔEnr of 0.19â eV. Furthermore, the ternary device comprising PB2 : PBDB-TF : BTP-Bme achieves an outstanding PCE of 19.3 %. The molecule design strategy in this study proposed new perspectives for developing high-performance acceptors with low ΔEnr in OSCs.
RESUMEN
In the field of organic photovoltaics (OPVs), significant progress has been made in tailoring molecular structures to enhance the open-circuit voltage and the short-circuit current density. However, there remains a crucial gap in the development of coordinated material design strategies focused on improving the fill factor (FF). Here, we introduce a molecular design strategy that incorporates electrostatic potential fluctuation to design organic photovoltaic materials. By reducing the fluctuation amplitude of IT-4F, we synthesized a new acceptor named ITOC6-4F. When using PBQx-TF as a donor, the ITOC6-4F-based cell shows a markedly low recombination rate constant of 0.66×10-14â cm3 s-1 and demonstrates an outstanding FF of 0.816, both of which are new records for binary OPV cells. Also, we find that a small fluctuation amplitude could decrease the energetic disorder of OPV cells, reducing energy loss. Finally, the ITOC6-4F-based cell creates the highest efficiency of 16.0 % among medium-gap OPV cells. Our work holds a vital implication for guiding the design of high-performance OPV materials.
RESUMEN
The development of high-efficiency organic solar cells (OSCs) processed from non-halogenated solvents is crucially important for their scale-up industry production. However, owing to the difficulty of regulating molecular aggregation, there is a huge efficiency gap between non-halogenated and halogenated solvent processed OSCs. Herein, we fabricate o-xylene processed OSCs with approaching 20 % efficiency by incorporating a trimeric guest acceptor named Tri-V into the PM6:L8-BO-X host blend. The incorporation of Tri-V effectively restricts the excessive aggregation of L8-BO-X, regulates the molecular packing and optimizes the phase-separation morphology, which leads to mitigated trap density states, reduced energy loss and suppressed charge recombination. Consequently, the PM6:L8-BO-X:Tri-V-based device achieves an efficiency of 19.82 %, representing the highest efficiency for non-halogenated solvent-processed OSCs reported to date. Noticeably, with the addition of Tri-V, the ternary device shows an improved photostability than binary PM6:L8-BO-X-based device, and maintains 80 % of the initial efficiency after continuous illumination for 1380â h. This work provides a feasible approach for fabricating high-efficiency, stable, eco-friendly OSCs, and sheds new light on the large-scale industrial production of OSCs.
RESUMEN
In the development of high-performance organic solar cells (OSCs), the self-organization of organic semiconductors plays a crucial role. This study focuses on the precisely manipulation of molecular assemble via tuning alkyl side-chain topology in a series of low-cost nonfused-ring electron acceptors (NFREAs). Among the three NFREAs investigated, DPA-4, which possesses an asymmetric alkyl side-chain length, exhibits a tight packing in the crystal and high crystallinity in the film, contributing to improved electron mobility and favorable film morphology for DPA-4. As a result, the OSC device based on DPA-4 achieves an excellent power conversion efficiency of 16.67 %, ranking among the highest efficiencies for NFREA-based OSCs.
RESUMEN
The structure of molecular aggregates is crucial for charge transport and photovoltaic performance in organic solar cells (OSCs). Herein, the intermolecular interactions and aggregated structures of nonfused-ring electron acceptors (NFREAs) are precisely regulated through a halogen transposition strategy, resulting in a noteworthy transformation from a 2D-layered structure to a 3D-interconnected packing network. Based on the 3D electron transport pathway, the binary and ternary devices deliver outstanding power conversion efficiencies (PCEs) of 17.46 % and 18.24 %, respectively, marking the highest value for NFREA-based OSCs.
RESUMEN
The response of crystal structure to external stimuli provides potential applications in the areas of detection, diagnosis, and repair. In this work, we fabricate two allotropic organic cocrystals, with different space groups and lattice parameters, with identical donor and acceptor molecules inside them. Under external stimuli, lattice vibration and electron-phonon coupling present pronounced differences in these two types of crystals, where different strengths of spin polarizations are observed. Furthermore, due to pronounced differences in coupling between lattice and spin inside the allotropic charge transfer crystals, the magnetic field presents a discrepant tunability on both transmission and fluorescence lifetimes. Through decreasing temperature or applying external electric field, the electron-phonon coupling coefficient presents a decreasing tendency, which will affect the dipole and dielectric constant in the allotropic crystals differently.
Asunto(s)
Electrones , Fonones , Electricidad , Campos Magnéticos , VibraciónRESUMEN
Organic photovoltaic (OPV) cells, with highly tunable light-response ranges, offer significant potential for use in driving low-power consumption off-grid electronics in multi-scenarios. However, development of photoactive layer materials that can meet simultaneously the requirements of diverse irradiation conditions is a still challenging task. Herein, a low-cost fully non-fused acceptor (denoted as GS60) featuring well-matched absorption spectra with solar, scattered light and artificial light radiation was designed and synthesized. Systematic characterizations revealed that GS60 possessed outstanding photoelectron properties and ideal morphology, which resulted in reduced voltage loss and suppressed charge recombination. By blending with a non-fused ring polymer PTVT-T, the as-obtained GS60 based OPV cells achieved a good power conversion efficiency (PCE) of 14.1 %, a high value for the cells based on non-fused ring bulk heterojunction. Besides, manufactured large-area OPV modules based on PTVT-T:GS60 yielded PCEs of 11.2 %, 11.8 %, 12.1 %, 23.1 %, and 20.3 % under irradiation of AM 1.5G, natural light of cloudy weather, natural light in shadow, laser and indoor, respectively. The PTVT-T:GS60 devices exhibited considerable potential in terms of improving photostability and reducing material cost. Overall, this work provides novel insight into the molecular design of low-cost non-fused ring acceptors, and extended potential of medium band gap acceptors based OPV cells used in various application scenarios.
RESUMEN
Solution-processing hybrid solar cells with organics and colloidal quantum dots (CQDs) have drawn substantial attention in the past decade. Nevertheless, hybrid solar cells based on the recently developed directly synthesized CQD inks are still unexplored. Herein, a facile polymer blending strategy is put forward to enable directly synthesized CQD/polymer hybrid solar cells with a champion efficiency of 13%, taking advantage of the conjugated polymer blends with finely optimized aggregation behaviors. The spectroscopic and electrical investigations on carrier transport and recombination indicate that polymer blends can endow fast carrier transport and less recombination over the single counterparts. Moreover, the blending strategy offers a "dilution effect" for top-notch photovoltaic polymers with excessively strong aggregation tendency, resulting in moderate feature domain size and surface roughness, which afford fast hole transport and therefore high photovoltaic performance. The effectiveness of this strategy is successfully validated using two pairs of photovoltaic polymers. Accordingly, the relationships between polymer morphology, carrier transport, and photovoltaic performance are established to advance the progress of CQD/polymer hybrid solar cells. Such progress stresses that the utilization of aggregation-suppressed polymer blends is a facile approach toward the fabrication of high-efficiency organic-inorganic hybrid solar cells.
RESUMEN
The efficiency of a hollow beam received by the Cassegrain antenna coupling into a single-mode fiber is low, and converting the hollow beam into a solid beam can remarkably improve the coupling efficiency. In this paper, shaping diffractive optical elements (DOEs) are designed through a modified Gerchberg-Saxton algorithm (MGS) with Fresnel diffraction. Further, the MGS algorithm can be applicable in the issue of circular symmetric beam shaping. The properties of the system with/without shaping DOEs are analyzed and compared. According to the simulation results, in consideration of the energy loss of the antenna, DOEs, and coupling lens, the total transmission efficiency of the receiving antenna system at 1550 nm wavelength can reach 77.81%. In addition, the system with shaping DOEs can better adapt for coupling lenses with different focal lengths, and the variation of the maximum coupling efficiency of the DOEs shaping system at different focal lengths studied in this paper is within 2.00%, which is 6.73% lower than that of the lens shaping system. The research results provide an idea of reverse design for improving a coupling system, which can also provide inspiration for other optical system designs.
RESUMEN
All-polymer solar cells (all-PSCs) possess excellent operation stability and mechanical robustness than other types of organic solar cells, thereby attracting considerable attention for wearable flexible electron devices. However, the power conversion efficiencies (PCEs) of all-PSCs are still lagging behind those of small-molecule-acceptor-based systems owing to the limitation of photoactive materials and unsatisfactory blend morphology. In this work, a novel terpolymer, denoted as PBDB-TFCl (poly4,8-bis(5-(2-ethylhexyl)-4-fluorothiophen-2-yl)benzo[1,2-b:4,5-bâ³]dithiophene-1,3-bis(2-ethylhexyl)-5,7-di(thiophen-2-yl)-4H,8H-benzo[1,2-c:4,5-câ³]dithiophene-4,8-dione-4,8-bis(4-chloro-5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene), is used as an electron donor coupled with a ternary strategy to optimize the performance of all-PSCs. The addition of PBDB-TCl unit deepens the highest occupied molecular orbital energy level, reducing voltage losses. Moreover, the introduction of the guest donor (D18-Cl) effectively regulates the phase-transition kinetics of PBDB-TFCl:D18-Cl:PY-IT during the film formation, leading to ideal size of aggregations and enhanced crystallinity. PBDB-TFCl:D18-Cl:PY-IT devices exhibit a PCE of 18.6% (certified as 18.3%), judged as the highest value so far obtained with all-PSCs. Besides, based on the ternary active layer, the manufactured 36 cm2 flexible modules exhibit a PCE of 15.1%. Meanwhile, the ternary PSCs exhibit superior photostability and mechanical stability. In summary, the proposed strategy, based on molecular design and the ternary strategy, allows optimization of the all-polymer blend morphology and improvement of the photovoltaic performance for stable large-scale flexible PSCs.
RESUMEN
Tartary buckwheat is rich in nutrients and its protein supports numerous biological functions. However, the digestibility of Tartary buckwheat protein (TBP) poses a significant limitation owing to its inherent structure. This study aimed to assess the impact of high moisture extrusion (HME, 60 % moisture content) on the structural and physicochemical attributes, as well as the in vitro digestibility of TBP. Our results indicated that TBP exhibited unfolded and amorphous microstructures after HME. The protein molecular weight of TBP decreased after HME, and a greater degradation was observed at 70 °C than 100 °C. In particular, HME at 70 °C caused an almost complete disappearance of bands near 35 kDa compared with HME at 100 °C. In addition, compared with native TBP (NTBP, 44.53 µmol/g protein), TBP subjected to HME at 70 °C showed a lower disulfide bond (SS) content (42.67 µmol/g protein), whereas TBP subjected to HME at 100 °C demonstrated a higher SS content (45.70 µmol/g protein). These changes endowed TBP with good solubility (from 55.96 % to 83.31 % at pH 7), foaming ability (20.00 %-28.57 %), and surface hydrophobicity (8.34-23.07). Furthermore, the emulsifying activity (EA) and in vitro digestibility are closely related to SS content. Notably, extruded TBP (ETBP) obtained at 70 °C exhibited higher EA and digestibility than NTBP, whereas ETBP obtained at 100 °C showed the opposite trend. Consequently, HME (especially at 70 °C) demonstrated significant potential as a processing technique for improving the functional and digestive properties of TBP.
Asunto(s)
Fagopyrum , Fagopyrum/química , Solubilidad , Digestión , Proteínas de Unión al GTP/metabolismoRESUMEN
The digestibility of ungelatinized, short-term retrograded and long-term retrograded starch from foxtail millet was investigated and correlated with starch chain length distributions (CLDs). Some variations in starch CLDs of different varieties were obtained. Huangjingu and Zhonggu 9 had higher average chain lengths of debranched starch and lower average chain length ratios of amylopectin and amylose than Dajinmiao and Jigu 168. Compared to ungelatinized starch, retrogradation significantly increased the estimated glycemic index (eGI), whereas significantly decreased the resistant starch (RS). In contrast, long-term retrograded starches have lower eGI (93.33-97.37) and higher RS (8.04-14.55%) than short-term retrograded starch. PCA and correlation analysis showed that amylopectin with higher amounts of long chains and longer long chains contributed to reduced digestibility in ungelatinized starch. Both amylose and amylopectin CLDs were important for the digestibility of retrograded starch. This study helps a better understanding of the interaction of starch CLDs and digestibility during retrogradation.
Asunto(s)
Amilopectina , Amilosa , Digestión , Setaria (Planta) , Almidón , Setaria (Planta)/química , Setaria (Planta)/metabolismo , Almidón/química , Almidón/metabolismo , Amilopectina/química , Amilosa/química , Índice GlucémicoRESUMEN
This study aimed to reveal the underlying mechanisms of the differences in viscoelasticity and digestibility between mung bean starch (MBS) and proso millet starch (PMS) from the viewpoint of starch fine molecular structure. The contents of amylopectin B2 chains (14.94-15.09 %), amylopectin B3 chains (14.48-15.07 %) and amylose long chains (183.55-198.84) in MBS were significantly higher than PMS (10.45-10.76 %, 12.48-14.07 % and 70.59-88.03, respectively). MBS with higher amylose content (AC, 28.45-31.80 %) not only exhibited a lower weight-average molar mass (91,750.65-128,120.44 kDa) and R1047/1022 (1.1520-1.1904), but also was significantly lower than PMS in relative crystallinity (15.22-23.18 %, p < 0.05). MBS displayed a higher storage modulus (G') and loss modulus (G'') than PMS. Although only MBS-1 showed two distinct and discontinuous phases, MBS exhibited a higher resistant starch (RS) content than PMS (31.63-39.23 %), with MBS-3 having the highest RS content (56.15 %). Correlation analysis suggested that the amylopectin chain length distributions and AC played an important role in affecting the crystal structure, viscoelastic properties and in vitro starch digestibility of MBS and PMS. These results will provide a theoretical and scientific basis for the development of starch science and industrial production of low glycemic index starchy food.
Asunto(s)
Amilopectina , Amilosa , Panicum , Almidón , Vigna , Amilopectina/análisis , Amilosa/análisis , Vigna/química , Almidón/química , Panicum/química , Pepsina A/metabolismo , Difracción de Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Peso Molecular , CinéticaRESUMEN
Starch chain-length distributions play a key role in regulating the processing and digestion characteristics of proso millet starch. Waxy proso millet starch has higher endothermic enthalpy (13.06-16.73 J/g) owing to its higher relative crystallinity (27.83%-32.04%), while nonwaxy proso millet starch has lower peak viscosity (1.0630-1.1930 Paâs) and stronger viscoelasticity owing to its higher amylose content (21.72%-24.34%). Non-waxy proso millet starch exhibited two different digestion phases and its resistant starch content (18.37%-20.80%) was higher than waxy proso millet starch. Correlation analysis showed proso millet starch with longer amylopectin B1 chains and more amylopectin B2 chains exhibited excellent thermal ability and retrograde resistance, whereas proso millet starch with shorter and more amylose medium/long-chains not only reduced the digestion rate and increased the resistant starch content but also exhibited stronger viscoelasticity and excellent retrogradation properties. These results could provide more insights into efficient utilization of proso millet starch.
Asunto(s)
Digestión , Almidón , Almidón/química , Almidón/metabolismo , Viscosidad , Amilosa/química , Amilosa/análisis , Amilosa/metabolismo , Amilopectina/química , Amilopectina/metabolismoRESUMEN
Component distribution within the photoactive layer dictates the morphology and electronic structure and substantially influences the performance of organic solar cells (OSCs). In this study, a molecular design strategy is introduced to manipulate component and energetics distribution by adjusting side-chain polarity. Two non-fullerene acceptors (NFAs), ITIC-16F and ITIC-E, are synthesized by introducing different polar functional substituents onto the side chains of ITIC. The alterations result in different distribution tendencies in the bulk heterojunction film: ITIC-16F with intensified hydrophobicity aligns predominantly with the top surface, while ITIC-E with strong hydrophilicity gravitates toward the bottom. This divergence directly impacts the vertical distribution of the excitation energy levels, thereby influencing the excitation kinetics over extended time periods and larger spatial ranges including enhanced diffusion-mediated exciton dissociation and stimulated charge carrier transport. Benefitting from the favorable energy distribution, the device incorporating ITIC-E into the PBQx-TF:eC9-2Cl blend showcases an impressive power conversion efficiency of 19.4%. This work highlights side-chain polarity manipulation as a promising strategy for designing efficient NFA molecules and underscores the pivotal role of spatial energetics distribution in OSC performance.
RESUMEN
Dipole moment arrangement in organic semiconductors plays a critical role in affecting the intermolecular packing, determining optoelectronic properties and device performance. Here, to get the desired fill factor (FF) values in organic solar cells (OSCs), the local dipole of non-fullerene acceptors (NFAs) is modulated by changing the molecular asymmetries. Two NFAs, AA-1 and AA-2 are designed and synthesized, which have different substitutions of alkyl and alkoxyl groups. The unidirectional asymmetry in AA-2 creates distinct local dipoles, while the bidirectional asymmetry in AA-1 mitigates dipole variation. Despite the minimal impact on monomolecular properties, the local dipole moment significantly influences terminal group packing modes in the film state. This, in turn, enhances the relative dielectric constant, prolongs exciton lifetime, and reduces sub-bandgap defect states. Consequently, PBDB-TF:AA-2-based OSCs achieve an exceptional FF of 0.830 and a power conversion efficiency (PCE) of 18.3%, with a ternary device reaching a PCE of 19.3%. This work highlights the potential of dipole modulation in material design to get ideal FF values for high-performance OSCs.