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In this paper, water-soluble CdTe quantum dots (QDs) with different sizes from 3 to 3.9 nm are synthesized by the aqueous phase method using glutathione as the stabilizer, and their fluorescence pr...

Summary Semitransparent organic solar cells (ST-OSCs) can potentially meet the huge demands of off-grid and rooftop power supplies for advanced agricultural activities; yet, only a few efforts have been devoted to its development. Herein, we developed a high-performance spectrally engineered ST-OSCs using “green” fabrication for greenhouse. Empowered by the newly designed quaternary blends, OSCs were obtained with an excellent power conversion efficiency (PCE) of 17.71%. Such quaternary blends not only exhibit the suitable photon transmission windows for plant absorption but also retain excellent photovoltaic properties upon non-halogenated solvent fabrication, leading to PCEs of 17.43% for opaque and 13.08% for ST-OSCs (with a plant growth factor of 24.7%), which represent the best-performed OSCs made from non-halogenated solvents. Under the ST-OSCs filtered lights, plants grow favorably, with growth being comparable with that under glass. This work provides an effective approach to constructing organic solar cells with promising features as eco-friendly greenhouse photovoltaics.

When facing some emergency situations, such as fires, traffic accidents, etc., it is necessary for the network to use the available information to provide the best and fastest access routes. In these cases, it is important to centrally manage all devices throughout the network, so a software-defined network (SDN) -based architecture is used to manage and control emergency service actions and evacuation plans. At this time, differentiated services are provided to customers in emergency and non-emergency situations through network slicing, and resource allocation is performed for network slicing such as delay and bandwidth parameters. In this paper, the first resource management plan is the merit of quick converging to the global optimal solution which was used to design the evaluation function of the network resource management; the second is monitors and analyzes access traffic and centralizes control and management to meet the bandwidth requirements of tenants to counter the tidal effect. The ability of fast random search of particle swarm optimization was used to realize the update and optimization. The simulation results show that can reduce the energy consumption of the network and improve the utilization rate of cyber source at the same time.

Organic solar cells (OSCs) with visible transparency and vivid colors are promising for deployment in building-integrated photovoltaics (BIPVs), yet significant challenges remain to be addressed fo...

Although promising progress has been made in near-infrared (NIR) electron acceptors for broadening photoresponse of optoelectronics, there are still strong needs for efficient NIR materials with low synthetic complexities. In this work, three simple NIR acceptors are developed with absorption up to 1000 nm and possessing the same dithiophene cores with varied heteroatom linkages to carbon (C) atom for W1, to silicon (Si) for W2, and to nitrogen (N) for W3. It is found that the tuning of only one atom for simple acceptors can surprisingly lead to a large difference in photoelectric properties and solid stacking, as well as the performance in optoelectronics. Although quite simple, these electron acceptors, especially W1 (C), can also perform quite efficiently as organic photovoltaics (OPVs) as well as sensitive organic photodetectors (OPDs) when blended with PTB7-Th polymer. It is worthy to note that, among the representative NIR acceptors with over 950 nm absorption, W1 possesses one of the best figure-of-merit when considering the photoelectric performance versus synthetic complexity of materials. As a result, the PTB7-Th:W1-based OPDs reach a fast temporal response, ultralow-light intensity detection of 1.70 × 10-11 W·cm-2, and a high specific detectivity of 4.28 × 1012 cm·Hz1/2·W-1 at 830 nm, representing a highly sensitive self-powered OPD approach the commercial broadband silicon detectors. These simple structure materials provide a potential example for further application of NIR electron acceptor.

The recent evolution of active components yielded brilliant progresses for organic solar cells (OSCs), yet the mechanism is needed to be clearly understood. In this work, two electron acceptors, a linear SN6-2Br and a V-shaped BTP-2Br, are developed with nitrogen atoms introduced to replace the traditional sp3-hybridized carbon in the fused ring. BTP-2Br possesses an electron-deficient central core, which exhibits slightly blue-shifted absorption as well as deepened HOMO-level compared with SN6-2Br. The corresponding photovoltaic performance from V-shaped BTP-2Br based devices exhibit superior performance especially in short-circuit current (Jsc), despite an enhanced absorption and charge carrier mobilities for SN6-2Br. The primary reason for the higher Jsc from BTP-2Br is faster exciton diffusion and dissociation in blends, than those of SN6-2Br. As a result, PBDB-TF:BTP-2Br based devices achieve a power conversion efficiency (PCE) of 13.84% with an voltage-loss of only 0.46 V, which is one of the lowest values ever reported. Moreover, we fabricated semitransparent OSCs that exhibit an excellent PCE of 9.62% with average visible transparency of 20.1%.

Semitransparent organic solar cells (ST-OSCs) have the potentials to open promising applications that differ from those of conventional inorganic ones, such as see-through power windows with both energy generation and heat insulation functions. However, to achieve so, there remain significant challenges, especially for balancing critical parameters, such as power conversion efficiency (PCE), average visible transparency (AVT) and low energy infrared photon radiation rejection (IRR) to realize the full potentials of ST-OSCs. Herein, we demonstrate the new design of ST-OSCs through the rational integration of organic materials, transparent electrode and infrared photon reflector in one device. With the assistance of optical simulation, new ST-OSCs with precise layout exhibit state-of-art performance, with near 30% AVT and PCE of 7.3%, as well as an excellent IRR of over 93% (780–2500 nm), representing one of best multifunctional ST-OSCs with promising perspective for window application.

Despite having attractive stability over the volatile methylammonium (MA) cation, double cation (Cs, FA) perovskite solar cells are largely overlooked due to inferior performance compared to MA-bas...

The photon energy losses of polymer solar cells (PSCs) routinely drag their experimental power conversion efficiencies (PCEs) far below the theoretical limits. We report herein efficient triple-jun...

With the recent emergence of a new class of high-performance nonfullerene acceptors (NFAs), organic solar cells (OSCs) have entered a new phase of research featuring high power conversion efficienc...

Developing near infrared (NIR) organic semiconductors is indispensable for promoting the performance of organic solar cells (OSCs), but addressing the trade-off between voltage and current density thus achieving high efficiency with low energy loss is still an urgent challenge. Herein, NIR acceptors (H1, H2 and H3) with a photoresponse beyond 1000 nm were developed by conjugating dithienopyrrolobenzothiadiazole to 2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrileviavaried alkyl thiophene bridges. It was found that the linear outward chains in thiophene bridges could mitigate both the conformation disorder of H3 and the electronic disorder of the PBDB-T:H3 blends, which could help to form a favorable blend morphology, facilitating highly efficient photoelectric conversion in the resultant OSCs. As a result, devices based on PBDB-T:H3 achieve a high efficiency of 13.75% with a low energy loss of 0.55 eV, which is one of the highest efficiencies and the lowest energy loss among OSCs with an optoelectronic response near 1000 nm. This work provides a new design strategy towards NIR acceptors for efficient OSCs and future exploration of functional optoelectronics. Funding Agencies|National Key Research and Development program of China [2019YFA0705900]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [21734008, 51803178, 61721005, 21722404, 21674093]; Zhejiang Natural Science Fund for Distinguished Young Scholars [LR17E030001]; NSFC/RGC Joint Research SchemeNational Natural Science Foundation of China (NSFC) [N_CUHK418/17]; Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation [2016.00590]; Government Strategic Research Area in Material Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [200900971]; China Scholarship Council (CSC)China Scholarship Council

Organic electrochemical transistors (OECTs) are currently being developed for applications ranging from bioelectronics to neuromorphic computing. We show that fullerene derivatives with glycolated side chains can serve as n-type active layers for OECTs with figures of merit exceeding the best reported conjugated-polymer-based n-type OECTs. By comparing two different fullerene derivatives, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and 2-(2,3,4-tris(methoxtriglycol) phenyl) [60]fulleropyrrolidine (C60-TEG), we find that the hydrophilic glycolated side chains in C60-TEG enable volumetric doping of C60-TEG films. In contrast, the hydrophobic nature of PCBM prevents ions from penetrating into the material. Our results demonstrate that small-molecule semiconductors follow many of the same design principles established for conjugated polymers and can function as high-performing mixed electronic/ionic conductors for efficient, fast OECTs.

Poly(3-hexylthiophene) (P3HT) is a low-cost polymer donor for organic solar cells (OSCs). However, the P3HT-based OSCs usually give low power conversion efficiencies (PCEs) due to the wide bandgap and the high-lying energy levels of P3HT. To solve this problem, in this work, we design and synthesize a new A-D-A type non-fullerene acceptor, DFPCBR, which owns an electron-donating (D) core constructed by linking a 2,5-difluorobenzene ring with two cyclopentadithiophene moieties, and two electron-accepting (A) end-groups of benzo[c][1,2,5]thiadiazole connected with 3-ethyl-2-thioxothiazolidin-4-one. Because of the strong electron-donating ability and large conjugation effect of D core, DFPCBR shows appropriate energy levels and a narrow bandgap matching well with those of P3HT. Therefore, with P3HT as the donor and DFPCBR as the acceptor, the OSCs possess broad absorption range from 350 nm to 780 nm and the reduced energy loss (Eloss) of 0.79 eV (compared with ∼1.40 eV for the P3HT:PC61BM device), providing a good PCE of 5.34% with a high open-circuit voltage (VOC) of 0.80 V. Besides, we observe that the photovoltaic performances of these devices are insensitive to the thickness of the active layers: even if the active layer is as thick as 320 nm, ∼80% of the best PCE is maintained, which is rarely reported for fullerene-free P3HT-based OSCs, suggesting that DFPCBR has the potential application in commercial OSCs in the future.

The flexibility in structural design of organic semiconductors endows organic solar cells (OSCs) not only great function-tunabilities, but also high potential toward practical application. In this work, simple non-fused-ring electron acceptors are developed through two-step synthesis from single aromatic units for constructing efficient OSCs. With the assistance of non-covalent interactions, these rotatable non-fused acceptors (in solution) allow transiting into planar and stackable conformation in condensed solid, promoting acceptors not only feasible solution-processability, but also excellent film characteristics. As results, decent power conversion efficiencies of 10.27% and 13.97% can be achieved in single and tandem OSCs consisting of simple solution-cast blends, in which the fully unfused acceptors exhibit exceptionally low synthetic complexity index. In addition, the unfused acceptor and its based OSCs exhibit promising stabilities under continuous illumination. Overall, this work reveals valuable insights on the structural design of simple and effective electron acceptors with great practical perspectives., Non-fullerene electron acceptors have pushed the efficiency of organic solar cells up to 15% but they all contain fused rings and are inconvenient to synthetic access. Here Yu et al. develop fully unfused acceptors featuring non-covalent intramolecular interactions, high efficiencies and high stability.

A sensitive enzyme-linked immunosorbent assay (ELISA) has been developed based on the dual catalysis of dendritic Pd-Pt porous nanoparticles and horseradish peroxidase (HRP). The Pd-Pt porous nanoparticles, for the first time, were used to immobilize HRP. As a proof-of-concept demonstration, HRP functioned Pd-Pt porous nanoparticles were applied in hCG detection with a detection limit of 0.07 IU L−1. The linear intervals is 0.1–6.4 IU L-1. The Pd-Pt-HRP possesses a better sensitivity than the traditional BA-ELISA. Furthermore, the precision and reproducibility and selectivity were assessed to be eligible for the hCG monitoring.

Photo-degradation of organic semiconductors remains as an obstacle preventing their durable practice in optoelectronics. Herein, we disclose that volume-conserving photoisomerization of a unique series of acceptor-donor-acceptor (A-D-A) non-fullerene acceptors (NFAs) acts as a surrogate towards their subsequent photochemical reaction. Among A-D-A NFAs with fused, semi-fused and non-fused backbones, fully non-fused PTIC, representing one of rare existing samples, exhibits not only excellent photochemical tolerance in aerobic condition, but also efficient performance in solar cells. Along with a series of in-depth investigations, we identify that the structural confinement to inhibit photoisomerization of these unique A-D-A NFAs from molecular level to macroscopic condensed solid helps enhancing the photochemical stabilities of molecules, as well as the corresponding OSCs. Although other reasons associating with the photostabilities of molecules and devices should not excluded, we believe this work provides helpful structure-property information toward new design of stable and efficient photovoltaic molecules and solar cells., Non-fullerene acceptors have contributed hugely to the best-performing organic solar cells, yet the photo-degradation remains a hurdle preventing the practical application. In this work, research group from Zhejiang University discovers non-fused acceptors with excellent photochemical tolerance in aerobic condition, and identify the main degradation pathway.

Ali CMB Polarization Telescope (AliCPT-1) is the first CMB degree-scale polarimeter to be deployed on the Tibetan plateau at 5,250m above sea level. AliCPT-1 is a 90/150 GHz 72 cm aperture, two-lens refracting telescope cooled down to 4 K. Alumina lenses, 800mm in diameter, image the CMB in a 33.4{\deg} field of view on a 636mm wide focal plane. The modularized focal plane consists of dichroic polarization-sensitive Transition-Edge Sensors (TESes). Each module includes 1,704 optically active TESes fabricated on a 150mm diameter silicon wafer. Each TES array is read out with a microwave multiplexing readout system capable of a multiplexing factor up to 2,048. Such a large multiplexing factor has allowed the practical deployment of tens of thousands of detectors, enabling the design of a receiver that can operate up to 19 TES arrays for a total of 32,376 TESes. AliCPT-1 leverages the technological advancements in the detector design from multiple generations of previously successful feedhorn-coupled polarimeters, and in the instrument design from BICEP-3, but applied on a larger scale. The cryostat receiver is currently under integration and testing. During the first deployment year, the focal plane will be populated with up to 4 TES arrays. Further TES arrays will be deployed in the following years, fully populating the focal plane with 19 arrays on the fourth deployment year. Here we present the AliCPT-1 receiver design, and how the design has been optimized to meet the experimental requirements., Comment: Proc. SPIE, 11453, 114532A (2020)

Cancer drugs which are specifically targeted at mitosis have generally under-delivered as a class. One likely reason is that only a small percentage of cancer cells in a tumor are actually dividing at any moment. If this is the case, then prolonged bioavailability in the tumor should significantly increase the efficacy of antimitotic agents. Here, we show that if the Plk1 inhibitor BI 2536 is co-encapsulated in a liposome with a pair of anions, its release rate is dependent on both the identity and stoichiometry of the anions. We created a library of liposomes with varying release rates using this approach and found that liposomal drug release rates correlated inversely with in vitro cancer cell killing. Xenografted mice treated with a single dose of slow-releasing liposomal BI 2536 experienced tumor volume decreases lasting 12 days and complete responses in 20% of mice. Treatment with two doses a week apart increased the response rate to 75%. This approach, which we termed Paired Anion Calibrated Release (PACeR), has the potential to revive the clinical utility of antimitotic cancer drugs which have failed clinical trials.

Lead halide perovskites, such as methylammonium lead iodide (MAPbI3) can reach near 100% internal quantum efficiency in single solar cells, but they still encounter significant thermodynamic losses in photon energy to offset device photovoltage and performance. Herein, a novel prismatic perovskite solar cell with light trapping configuration, namely, Prim PVSC, is designed to mitigate such losses in devices, through modulating the pathway of light inside series cells, wherein incident high-to-low energy photons are separately captured by four horizontally aligned MAPbIxBr3−x subcells with varied bandgaps. This newly designed PVSC has remarkably led to a record open circuit voltage of 5.3 V in four series devices and power conversion efficiency of 21.3%, which could provide a new way to break the performance bottleneck of perovskites. Practically, this type of device architecture could also be applied in flexible modules for large-area application.

Dry eye disease (DED) is characterized by increased osmolality of tears due to a lack of production or increased evaporation of tears. Hyperosmolarity is involved in DED pathogenesis, which damages ocular surface cells and leads to inflammation of the ocular surface. We investigated the anti-inflammatory effect of paeoniflorin (PF) from Paeonia lactiflora Pall. on human corneal epithelial (HCE) cells and its molecular mechanisms, and its therapeutic effects on a mouse model of experimental dry eye (EDE). HCE cells were treated with PF-1 (PF prepared in vitro; 0.01%, 0.1% and 1.0%). Protein production/activity was determined by Western blotting, RT-PCR and immunofluorescent staining. Meanwhile, eye drops containing 0.01%, 0.1% and 1.0% of PF-2 (PF prepared in vivo) were applied to the EDE, and the tear volume, corneal fluorescein-staining score, detachment of the corneal epithelium, and immunohistochemical staining were measured after 28 days of treatment. PF reduced expression of proinflammatory factors such as interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α in HCE cells, and significantly improved dry-eye signs, including tear volume, desquamation of the corneal epithelium and ocular surface inflammation in mice treated with 1.0% PF-2. Further study showed that PF improved EDE by inhibiting mitogen-activated protein kinase (MAPK), phosphorylated (p)-c-Jun N-terminal kinase (JNK) and pp-38, and nuclear factor kappa B (NF-κB) signaling pathways. These data suggest that PF can improve dry-eye symptoms and reduce expression of proinflammatory mediators. Hence, eye drops containing PF could be used as an adjunctive treatment for DED.

Herein, two new electron acceptors, BTTPC and BTTPC-Br, are developed through extending the conjugation of terminal electron accepting moieties with thiophene and bromine units. Such a structural design effectively improves the hole transfer of exciton dynamics in blends, revealing that BTTPC-Br and BTTPC based blends, in the presence of a smaller energetic offset as a driving force, exhibit faster hole transfer from acceptors to the polymeric donor interface, 4 times (BTTPC-Br) and 1.5 times (BTTPC) faster than 0.44 picoseconds of unmodified Y5. As a result, organic solar cells (OSCs) based on the BTTPC-Br acceptor, outperforming those of BTTPC:PBDB-T and Y5:PBDB-T, reach a power conversion efficiency of 15.22%, which is so far one of the highest among the single junction OSCs made with PBDB-T polymer donor.

Here we designed and synthesized a new small molecule donor DRC4TB with an alkylthiothienyl-substituted benzodithiophene as the core and 3-butyl rhodanine as the terminal group, which showed an optical bandgap of 1.87 eV. DRC4TB was compatible with both a fullerene acceptor (PC71BM) and an unfused-ring nonfullerene acceptor (HF-PCIC). The optimized DRC4TB:PC71BM and DRC4TB:HF-PCIC solar cells delivered comparable power conversion efficiencies (PCEs) of 8.53% and 8.68%, respectively.

The absorption of nonfullerene acceptors (NFAs) at near-infrared (NIR) regions is crucial for obtaining high current densities in organic solar cells (OSCs). Herein, two narrow-band gap NFAs with unfused backbones possessing broad (600-900 nm) and strong absorption are developed by the conjugation of a benzothiadiazole core to halogenated end groups through a cyclopentadithiophene bridge. Compared with the fluorinated counterpart BCDT-4F, the chlorinated NFA BCDT-4Cl shows stronger J-aggregation and closer molecular packing, leading to an optimized blend morphology when paired with the polymer donor, PBDB-T. Thus, an obvious improvement in external quantum efficiency response was obtained for BCDT-4Cl-based OSCs, presenting a higher efficiency of 12.10% than those (9.65%) based on BCDT-4F. This work provides a design strategy for NIR acceptors in the combination of electron-deficient core and halogenated terminal in unfused backbones, which results in not only fine-tuning the optoelectronic properties but also simplifying the synthetic complexities of molecules.

Clean energy production and saving play vital impacts on the sustainability of the global community. Herein, high-performance semitransparent organic solar cells (ST-OSCs) with excellent features of power generation, being see-through, and infrared reflection of heat dissipation, with promising perspectives for building-integrated photovoltaics (BIPVs) are reported. To simultaneously improve average visible transmittance (AVT) and power conversion efficiency (PCE), formally in a trade-off relationship, of ST-OSCs, new ternary blends with alloy-like near-infrared (NIR) acceptors are employed, which are effective to improve device efficiency while maintaining visible absorption unchanged, resulting in PCEs of 16.8% for opaque devices and 13.1% for semitransparent OSCs (AVT of 22.4% and infrared photon radiation rejection (IRR) of 77%). Further, multifunctional ST-OSCs are realized via introducing simple, yet effective photonic reflectors, together with optical simulation, leading to not only perfect fitting of the visible transmittance peak (555 nm) to the photopic response of the human eye but also an excellent IRR of 90% (780-2500 nm), along with 23% AVT and over 12% PCE. This is thought to be the best-performing multifunctional ST-OSC with promising prospects as BIPVs in terms of power generation, heat dissipation, and being see-through.

To further advance polymer solar cells requires the fast evolution of π-conjugated materials as well as a better understanding of their structure-property relationships. Herein, we present three copolymers (PT1, PT2, PT3) made through tuning π-bridges (without any group, thiophene, and 3-hexylthieno[3,2- b]thiophene) between electron-rich (D: BDTT) and -deficient (A: BDD) units. The comparative studies reveal the unique correlation that the tune of π-bridge on the polymeric backbone governs the solid stacking and photovoltaic properties of resultant poly(BDTT- alt-BDD)s, which provide an effective way to deliver new and efficient polymer with feasible processability. That is, polymers with either twist zigzag backbone (PT1) or with linear coplanar backbone (PT2) result in inferior photovoltaic performance upon simple solution casting. Among them, PT3 with extended zigzag backbone and planar segments exhibits suitable processability and retains good efficiency in nonfullerene solar cells through a single-solvent cast without involving tedious treatments. This work illustrates that the tuning of the D-π-A polymer backbone facilitates efficient materials with feasible processability, promising for scale-up fabrication.

Amplifying the signal of ELISA is important in the early disease diagnosis. Herein we report an ultrasensitive ELISA applying for the detection of hCG based on the assemble of AuNPs induced by functional PAMAM. The AuNP-PAMAM probe shows a competitive advantage sensitivity of 0.03 IU L-1 compared to traditional ELISA and mAb1-AuNP-HRP probe. The line range is ranged from 0.1 to 6.4 IU L-1. Moreover, the precision and reproducibility and specificity of AuNP-PAMAM probe are also eligible for the detection of hCG. The assembled AuNPs was firstly used in the signal enhancement in immunoassay.

Non-fullerene organic solar cells (OSCs) have attracted great attention due to their advantages such as tunable energy levels, reduced energy loss, strong light absorption. Here, three small molecules with polar functional groups were utilized to modify the surface of zinc oxide (ZnO) electron transport layer through self-assembled monolayers (SAMs) formation. Inverted non-fullerene OSCs with PBDB-T:ITIC blend as active layer based on the ZnO with SAMs modification showed enhanced device performance (10.90%) compared to that without SAM treatment (10.03%). The ultraviolet photoelectron spectroscopy results revealed that the SAMs could lower the surface work function of ZnO, allowing for better electron extraction. The analysis results of J-V characteristics under different light illumination intensities suggested more efficient charge dissociation and weaker trap-assisted bimolecular recombination in the devices with SAMs modification. Our work provides an effective approach to modify the ZnO surface for efficient non-fullerene OSCs.

The Huangshandong Ni–Cu sulfide deposit, located in the Kangguer–Jing’erquan ductile shear zone, belongs to the Jueluotage island arc belt in Eastern Tianshan of the Central Asian Orogenic Belt. The Huangshandong mafic–ultramafic pluton, which has a fusiform shape, is believed to have intruded strongly foliated Late Carboniferous volcanic rocks during the development of the regional ductile shear zone. Some orebodies in the deposit show intense ductile deformation. Among them, the No. 17 orebody is entirely controlled and hosted by the ductile shear zone. Host rocks and ores from this orebody show intense deformation and alteration, and could be called ore mylonites. Furthermore, numerous anastomosing veinlets can be observed in copper-rich carbonate-sulfide veins in the ductile shear zone. Geological field investigation and ore petrography studies indicate that sulfide ores at Huangshandong are composed of three types: undeformed magmatic ores, deformed magmatic ores, and hydrothermal overprinted ores. Magmatic ores with net fabrics remain unaltered and undeformed, and sulfide minerals in them show only brittle fractures. Silicate and sulfide minerals in deformed magmatic ores are characterized by intense deformation fabrics. Examples for such fabrics are kink bands, wavy extinction of uralite, domino structure of phlogopite, and elongated grains of pyrrhotite and pentlandite. Hydrothermal overprinted ores are characterized by strong deformation, flattened grains, and recrystallization of pyrrhotite; moreover, annealing of pyrrhotite is frequently observed. Pyrrhotite, pentlandite, and chalcopyrite in hydrothermal overprinted ores have high Ni and Co concentrations in pyrrhotite, a higher Ni concentration in pentlandite, and high Ag and Cd concentrations, respectively. We attribute Ni and Co in fluid-overprinted ores mainly to the alteration of olivine, and the dissolution of primary chalcopyrite is the likely source of copper in chalcopyrite-rich hydrothermal overprinted ores. During the intruding and cooling of the Huangshandong pluton, intense regional ductile shearing caused the ductile deformation of sulfide ores in the deposit, and subsequently, ore mylonites were formed. Gangue minerals in the deformed orebodies were crushed to fine-grained minerals and altered to serpentine, chlorite, and uralite. During these processes, fluid and ore elements were released and reacted with deformed rocks and ores, forming anastomosing veinlets on hydrothermal overprinted ores.

Two novel non-fullerene acceptors, SN6IC and SN6IC-4F, based on an S,N-heteroacene backbone were designed and synthesized. The cyclopentadiene fragments of commonly used acceptors were replaced with pyrrole rings to improve the electron-donating ability to increase the energy levels of the molecules. Both acceptors match well with the absorption and energy levels of the polymer donor PBDB-T, and PBDB-T:SN6IC-4F-based solar cells showed an excellent power conversion efficiency of 13.2%, with a relatively small VOC loss of 0.54 eV. This study proves that the introduction of a nitrogen atom to replace the sp3-hybridized carbon in the fused ring is very effective for making highly efficient NFAs to further improve the performance of organic solar cells.

A novel metal-free organic dye based on triarylamine functionalized by a carbazole unit is synthesized and used in solid state dye sensitized solar cells (sDSC). The carbazole is co-polymerized with bis-EDOT by in-situ photo-electrochemical polymerization leading to a hole transporting polymer material covalently bonded to the light active centre. These first photovoltaic performances results are promising in sDSCs applications.

Affected by beddings and natural fractures, fracture geometry in the vertical plane is complex in shale formation, which differs from a simple fracture in homogeneous sandstone reservoirs. However, the propagation mechanism of a hydraulic fracture in the vertical plane has not been well understood. In this paper, a true tri-axial pressure machine was deployed for shale horizontal well fracturing simulation experiments of shale outcrops. The effects of multiple factors on hydraulic fracture vertical propagation were studied. The results revealed that hydraulic fracture initiation and propagation displayed four basic patterns in the vertical plane of laminated shale formation. A hydraulic fracture would cross the beddings under the high vertical stress difference between a vertical stress and horizontal minimum stress of 12 MPa, while a hydraulic fracture propagates along the beddings under a low vertical stress difference of 3 MPa. Four kinds of fracture geometry, including a single main fracture, a nonplanar fracture, a complex fracture, and a complex fracture network, were observed due to the combined effects of flow rate and viscosity. Due to the influence of binding strength (or cementing strength) on the fracture communication effects between a hydraulic fracture and the beddings, the opening region of the beddings takes the shape of an ellipse.

A novel BODIPY-hemicyanine based fluorescent probe 1 for cyanide (CN − ) detection was designed and synthesized. Among the tested anions, the probe showed high selectivity towards CN − . Only addition of CN − to probe 1 in aqueous solution (V H2O /V EtOH = 1/1) could result in a remarkable blue shift of the absorption band from 385 nm to 265 nm and induce 20-fold fluorescence enhancement at 515 nm. The sensing mechanism was based on nucleophilic addition between CN − and indolium group, which was confirmed by 1 H NMR and mass spectrum analysis. Plot of fluorescence intensity as a function of CN − concentrations exhibited a good linear relationship in the range of 0–10 μM, with a detection limit to be 1.53 ppb. Moreover, the proposed sensing approach could work in a wide pH range from 5.0–9.0 and reach an equilibrium instantaneously. Finally, probe 1 was successfully applied in detection of CN − in natural water samples and on test paper strips with satisfactory results.

Conductive fullerene surfactants, FPPI, Bis-FPPI, Bis-FIMG and Bis-FITG, are developed as electron transporting materials for achieving efficient organic and perovskite solar cells (OSCs and PVSCs) under mild solution-fabrication. One common structural feature of these fullerenes is a quaternary ammonium halide moiety, which enables electron transfer from constituent Lewis basic halides to adjacent π-acidic fullerene, resulting in anion-induced n-doping of the derived fullerenes. These polar fullerenes, herein with suitable conductivities, work-function tunability and orthogonal solution-process abilities (to common organic semiconductors and perovskites), possess advantages as interlayers not only enabling good photovoltaic performance of OSCs and PVSCs, with over 19% power conversion efficiency made from mild fabrication, but also showing device performance insensitive to the interlayer thickness.

Although the power conversion efficiencies (PCEs) of polymer solar cells (PSCs) based on non-fullerene acceptors have been increasing rapidly over the last couple of years, little is known about the correlations between molecular structures and blend morphologies. In this work, we design and synthesize three acceptor–donor–core–donor–acceptor (A–D–C–D–A) type non-fullerene acceptors, HF–PCIC, HFO–PCIC and OF–PCIC, which possess the same electron-donating parts (D) and electron-accepting terminals (A), but different benzene-based cores (C). We observe that such minor chemical variations can lead to distinct differences in their photovoltaic properties. The resulting PSCs based on HF–PCIC with a 2,5-difluorobenzene core yield a good PCE of 10.97%, which is higher than those of HFO–PCIC and OF–PCIC based PSCs (8.36% and 9.09%). If the processing solvent is changed from chlorobenzene to chloroform, a further improved PCE of 11.49% is obtained for HF–PCIC-based PSCs due to the formation of finer phase separation domains. This is the highest value among the PSCs with non-fullerene acceptors possessing unfused cores. Through a series of characterization techniques, we disclose that the diverse benzene-based cores influence the molecular geometries of the three non-fullerene acceptors, resulting in varied molecular packing modes and film morphologies. The results suggest that the tuning of non-fullerene acceptors' geometries is an effective method to optimize the film morphology and thus the photovoltaic properties. The unfused-core in A–D–C–D–A small molecules provides a good building block to construct high-performance non-fullerene acceptors.

In this work, a new A–D–A type non-fullerene electron acceptor, DF-PCNC, which possesses an electron-donating (D) core constructed by linking a 2,5-difluorobenzene ring with two cyclopentadithiophene moieties and two electron-accepting (A) end-groups of 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1-ylidene)malononitrile (NC), is designed and synthesized. Because of the extension of the π-conjugation system, DF-PCNC shows stronger and more red-shifted absorption peaks while compared to those of its counterpart, DF-PCIC, which has the same D core but smaller A terminals of 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (IC). Furthermore, NC groups can enhance the intermolecular π–π stacking of DF-PCNC in the condensed state. Thus, when it is blended with a polymer donor, PBDB-T, to fabricate organic solar cells (OSCs), good morphologies of the blended films are achieved through appropriate optimizations: both donor and acceptor form highly crystalline phase-separation domains with appropriate nanoscaled sizes, which is beneficial to charge generation and transport in OSCs. As a result, the short-circuit current density (JSC) of the PBDB-T:DF-PCNC device is increased by 16% compared with that of the PBDB-T:DF-PCIC one, and a high fill factor (FF) of 72.62% is maintained, leading to a better power conversion efficiency (PCE) of 11.63%, which is the highest value for OSCs based on non-fullerene acceptors adopting decreased fused-ring D cores to date.

Two Bingel fullerenes, PCP and MCM, as electron transporting materials (ETMs) have been developed for achieving thick-film perovskite solar cells (PVSCs) with efficiencies beyond 19% with a planar absorber layer over 1 micrometer. Almost no PVSCs have exhibited PCEs above 18% with a 1 micrometer planar layer before, owing to the excess perovskite defects deteriorating charge extraction and the performance of thick-film based devices. Benefiting from the nearly identical optoelectronic properties of two ETMs stemming from tailored chemical structures, the studies on them allow us to unveil the fact that subtle molecular interaction (anion–π and Lewis acid–base) between ETMs and perovskites strongly affects the charge extraction at the heterointerface, which in turn influences the device hysteresis and performance. Particularly, weak Lewis base–acid O–Pb^(2+) interaction between MCM and the perovskite helps passivate the trap-states at the interface, resulting in a smooth electron extraction and reduced device hysteresis (the average hysteresis index (HI) of 0.03 ± 0.01). However, the strong N–Pb^(2+) coordination induces misalignment of the energy levels at the perovskite/PCP heterojunction, causing electron accumulation at the junction, and hence the large HI (0.17 ± 0.05) in devices. This work provides new insights into the charge extraction at the perovskite/organic interface and the possible molecular interaction from organics to cure perovskite defects.

The Huangshandong Ni–Cu sulfide deposit is the largest magmatic sulfide deposit in the Huangshan–Jing’erquan mafic–ultramafic belt in the Eastern Tianshan; it was overprinted by post-magmatic hydrothermal fluids, and metamorphosed and deformed as a result of regional ductile shearing. Ore-forming elements were remobilized as a result of post-magmatic hydrothermal fluid flow, but the extent of this remobilization is still unclear. In this contribution, detailed mineralogical–textural characteristics of silicates and base-metal sulfides in different types of ores in the Huangshandong Ni–Cu sulfide deposit were integrated with spatially resolved trace-element compositions of olivine, serpentine, pyrrhotite, pentlandite, and chalcopyrite to identify the metals that were mobilized, the scale and quantity of metal remobilization, and the phases into which the mobilized metals were incorporated. Based on varying degrees of serpentine and talc alteration, three different types of ores are identified – weakly serpentinized magmatic ores, which are most representative of the primary magmatic mineralization, strongly serpentinized and deformed ores, and talc-altered ores. The cracks consisting of serpentine and magnetite in weakly serpentinized magmatic ores caused by the expansion of olivine during serpentinization; this, serpentine is enriched in ore-forming metals (e.g., Ni, Co, Cu) relative to olivine. The expansion cracks extend from olivine to sulfides also enriched in ore-forming metals, suggesting that some metals were mobilized from olivine during serpentinization. Based on the higher Ni content of secondary pyrrhotite compared to primary pyrrhotite, it is suggested that base-metal sulfides in the primary, weakly serpentinized ores were dissolved and reprecipitated in the strongly serpentinized and deformed ores from metal-rich fluids that interacted with olivine.

A series of low band gap terpolymers based on 4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene (BDTT) and diketopyrrolopyrrole (DPP) with varied solubilizing groups ( i.e. , tert -butoxycarbonyl, t -Boc and 2-octyldodecyl) are developed as electron donors for bulk heterojunction (BHJ) polymer solar cells (PSCs). The results reveal that the one with 50% t -Boc concentration (P3) performs better than the other terpolymers used in this study in conventional PSC devices with a power conversion efficiency of 2.92%

In this paper, a non-fullerene electron acceptor, SF(DPPFB)4, which owns a spirobifluorene core and four diketopyrrolopyrrole (DPP) arms end capped by 4-fluorobenzene, is designed and synthesized for solution-processable organic solar cells (OSCs). SF(DPPFB)4 shows similar absorption bands as those of its non-fluorinated parent compound, SF(DPPB)4. However, the terminal fluorine atoms reduce the energy levels of SF(DPPFB)4, especially, its lowest unoccupied molecular orbital level decreases by 0.04 eV than that of SF(DPPB)4, which enlarges the energy offset between the electron donor and acceptor, favorable for the dissociation of excitons in OSCs. Moreover, the fluorination improves the electron mobility of SF(DPPFB)4. Thus, the OSCs with poly(3-hexylthiophene) as the electron donor and SF(DPPFB)4 as the electron acceptor can provide a maximum power conversion efficiency of 4.42%, with a lifted short-circuit current (Jsc) of 8.48 mA cm−2.

The alternating diketopyrrolopyrrole (DPP)-Quinoxaline (Qx) based conjugated polymers are synthesized and investigated as electron donors for polymer solar cells (PSCs). Through the substitution of phenyl in Qx unit at para (p) and meta (m) positions with methoxy group, the resultant DPP-pMQx and DPP-mMQx polymers possess narrow optical band gap (1.32 and 1.26 eV) with relatively low-lying highest occupied molecular orbitals. The obtained photovoltaic devices indicate that the combination of DPP with weak acceptor Qx is helpful to develop narrow bandgap polymers with near-infrared photo response and low energy loss (0.58 eV for DPP-mMQx) in PSC devices.

The ternary strategy for incorporating multiple photon-sensitive components into a single junction has emerged as an effective method for optimizing the nanoscale morphology and improving the device performance of organic solar cells (OSCs). In this study, efficient and stable ternary OSCs were achieved by introducing the small-molecule dye (5E,5′E)-5,5′-(4′,4″-(1,2-diphenylethene-1,2-diyl)bis(biphenyl-4′,4-diyl))bis(methan-1-yl-1-ylidene)bis(3-ethyl-2-thioxothia zolidin-4-one) (BTPE-Rn) into poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene-co-3-fluorothieno[3,4-b]thiophene-2-carboxylate] (PTB7-Th):[6,6]-phenyl C71 butyric acid methyl ester (PC71BM) blend films processed using a 1,8-diiodooctane (DIO)-free solvent. The incorporation of BTPE-Rn enhanced the short-circuit current density and fill factor of the ternary OSCs compared with those of binary OSCs. An investigation of the optical, electronic, and morphological properties of the ternary blends indicated that the third component of BTPE-Rn not only promoted the photon utilization of blends through the energy-transfer process but also improved the electron mobility of the blends owing to the fullerene-rich nanophase optimization. More importantly, this ternary strategy of utilizing a small-molecule dye to replace the photounstable DIO additive enhanced the operational stability of the OSCs.

The uniformity of the pore size and the morphology of nano-porous anodic alumina (nano-PAA) can be improved by a pore-widening process. The evolution of the pore diameter and the morphology was investigated in real time. Phosphoric acid solution (3wt%) was used as the etchant to chemically enlarge the pores of a nano-PAA prepared with oxalic acid. It is found that the pore-widening is carrying out simultaneously both on top-view and cross-section. From the top-view analysis, the pore diameter gradually enlarges with the increasing of etching time. However, such enlarging rate varies with the multilayer structure of the pore wall. From the cross-section analysis, the pores walls of a multilayered amorphous compound are etched in a stage-by-stage mode until almost everything is etched away. The pore-widening procedure on the upper portion is completed earlier respect to the lower portion, after some time the pore-widening becomes uniform along the axial direction. If the etching is maintained, hexagonal pore walls will be destroyed and split into ultrahigh aspect ratio nanowires due to the etching anisotropy, and finally completely dissolved. Combining analyses in the depth direction with stereoscopic 3D imaging the results clarify the pore-widening mechanism in 3D nano-PAA.

The Cathaysia Block is the southeastern part of the South China Block in Southeast (SE) China, and it hosts voluminous late Mesozoic I-, S-, and A-type granitoids, as well as minor highly fractionated granites. We present here zircon U–Pb age data and Nd–Hf isotopic data for the Dayang and Juzhou granites, together with new petrological and geochemical analyses. The Dayang pluton consists of fine-grained two-mica monzonitic granites in which the plagioclases exhibit zoning and poikilitic textures. In contrast, the Juzhou pluton consists of medium- to coarse-grained biotite K-feldspar granites that lack zoning and poikilitic textures. The emplacement ages are 143 ± 2.3 Ma for the Dayang pluton and 133 ± 2.1 Ma for the Juzhou pluton according to zircon U–Pb isotope analyses. The Dayang and Juzhou granites are both metaluminous and belong to the shoshonitic series. The Dayang granite exhibits very flat REE patterns, showing the tetrad effect, and the spidergrams show striking negative Ba, Sr, Nb, and Ti anomalies and a positive Ta anomaly. In contrast, the Juzhou granite has sloping REE patterns, but like the Dayang granite it also has striking negative Ba, Sr, Nb, Ta, and Ti anomalies. Petrographic and geochemical evidence indicates that the Dayang granite is a highly fractionated I-type granite and that the Juzhou granite is a typical I-type granite. The tetrad effect in the Dayang granite can be interpreted in terms of melt–rock interactions at a late stage of magma evolution, whereas the main mechanism during the evolution of the Juzhou magma was fractionation of plagioclase, biotite, hornblende, apatite, zircon, and allanite. Nd–Hf isotope data suggest that the Dayang and Juzhou granites were both formed partial melting of Paleoproterozoic basement rock and juvenile material (underplating basalts or Mayuan Group amphibolites), with the Juzhou granite having a greater contribution from juvenile material than the Dayang granite. Our new data, together with existing data, suggest that the tectonic setting of the early Yanshanian (∼143 Ma) highly fractionated I-type Dayang granite was a back-arc that formed in response to the westward subduction of the Paleo-Pacific Plate, and that the late Yanshanian (∼133 Ma) Juzhou granite formed in a continental arc setting in response to rollback of the Paleo-Pacific Plate toward the coastline. The Mo mineralization in the Makeng ore area was probably the result of the exsolution of Mo-bearing fluids from the Dayang granitic magmas due to extensive fractional crystallization.

pH responsive polymeric nanoparticles have emerged as a promising technology platform for targeted and controlled drug delivery in recent years. In this paper, endosomal pH-activatable doxorubicin (DOX) and core-crosslinked polymeric nanoparticles (DCNPs) were prepared and investigated for potent growth inhibition of human cancer cells in vitro. In vitro drug release studies, DOX conjugated nanoparticles with hydrazone bond showed a pH sensitive release phenomenon, that is, the releasing is significantly faster at mildly acidic condition with pH of 5.5 than that at physiological condition. Confocal laser scanning microscope (CLSM) observations revealed that DOX conjugated nanoparticles delivered and released DOX into the cytosols as well as cell nuclei of Hela cells following 6 h incubation. MTT assays demonstrated that these pH-sensitive DOX nanoparticles exhibited high antitumor effect to HeLa cells. The conjugated DOX polymeric nanoparticles may be a promising candidate as a nanoscale and pH-sensitive drug delivery vehicle for cancer therapy.

In this review, we highlight the recent development of organic π-functional materials as buffer layers in constructing efficient perovskite solar cells (PVSCs). By following a brief introduction on the PVSC development, device architecture and material design features, we exemplified the exciting progresses made in field by exploiting organic π-functional materials based hole and electron transport layers (HTLs and ETLs) to enable high-performance PVSCs.

Low energy loss and efficient charge separation under small driving forces are the prerequisites for realizing high power conversion efficiency (PCE) in organic photovoltaics (OPVs). Here, a new molecular design of nonfullerene acceptors (NFAs) is proposed to address above two issues simultaneously by introducing asymmetric terminals. Two NFAs, BTP-S1 and BTP-S2, are constructed by introducing halogenated indandione (A(1)) and 3-dicyanomethylene-1-indanone (A(2)) as two different conjugated terminals on the central fused core (D), wherein they share the same backbone as well-known NFA Y6, but at different terminals. Such asymmetric NFAs with A(1)-D-A(2) structure exhibit superior photovoltaic properties when blended with polymer donor PM6. Energy loss analysis reveals that asymmetric molecule BTP-S2 with six chlorine atoms attached at the terminals enables the corresponding devices to give an outstanding electroluminescence quantum efficiency of 2.3 x 10(-2)%, one order of magnitude higher than devices based on symmetric Y6 (4.4 x 10(-3)%), thus significantly lowering the nonradiative loss and energy loss of the corresponding devices. Besides, asymmetric BTP-S1 and BTP-S2 with multiple halogen atoms at the terminals exhibit fast hole transfer to the donor PM6. As a result, OPVs based on the PM6:BTP-S2 blend realize a PCE of 16.37%, higher than that (15.79%) of PM6:Y6-based OPVs. A further optimization of the ternary blend (PM6:Y6:BTP-S2) results in a best PCE of 17.43%, which is among the highest efficiencies for single-junction OPVs. This work provides an effective approach to simultaneously lower the energy loss and promote the charge separation of OPVs by molecular design strategy. Funding Agencies|National Key Research and Development Program of China [2019YFA0705900]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China [21734008, 21875216, 51803178, 61721005]; China Postdoctoral Science FoundationChina Postdoctoral Science Foundation [2017M621907, 2019T120501]; S&T Innovation 2025 Major Special Programme of Ningbo [2018B10055]; Research Grant Council of Hong KongHong Kong Research Grants Council [N_CUHK418/17, 14303519, 4053304]; Swedish Government Strategic Research Area in Material Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [200900971]; Swedish Research CouncilSwedish Research Council [2017-04123]; China Scholarship Council (CSC)China Scholarship Council

International audience; A global burden of Alzheimer's disease (AD) has been growing over last decades. Evidence indicates that β-amyloid (Aβ) production and senile plaque deposition in the brain is causative in the onset of AD pathogenesis. It appears much earlier than cognitive decline and plays a key role in initiating and developing AD neuropathology. As such, there is an intense passion with discovering theranostic agents which make a significant impact in diagnostic and therapy. Herein, we report an investigation of novel phenothiazine-based compounds as promising potential theranostic agents for AD. Remarkably, they have exhibited a high binding affinity toward Aβ aggregates, a good biostability and a strong increase in their fluorescence intensity with blue shift when interacting with Aβ aggregates. Furthermore, they have been simultaneously applied to perform NIR in vivo imaging of β-amyloid plaques in double transgenic AD mouse model, to prevent self-aggregation of Aβ monomer from forming toxic oligmers and to reduce Aβ-induced toxicity of human neuroblastoma cells (SH-SY5Y).

Considering the vast surface areas of windows and facades in modern urban environments, developing building-integrated photovoltaics employing transparent photovoltaic cells provides an opportunity to convert solar energy to electricity rather than generating waste heat. In this work, a non-fullerene acceptor based near-infrared (NIR) absorbing ternary component cell combined with a thin, semitransparent, high conductivity Cu-Ag alloy electrode was used to demonstrate semitransparent organic photovoltaic cells (ST-OPVs). A combination of optical outcoupling and anti-reflection coatings leads to enhance visible transmission, while reflecting the NIR back into the cell where it is absorbed. The optimized devices have the light utilization efficiency (LUE), which is equal to the product of the power conversion efficiency (PCE) and the average photopic transparency compared with a conventional semitransparent cell, twice that of a cell lacking these coatings. A maximum LUE = 3.56± 0.11% is achieved for a ST-OPV with a PCE = 8.0± 0.2%% at 1 sun, AM1.5G simulated emission.

The Tianshan is one of the largest gold provinces on Earth and hosts several giant gold deposits, while most giant gold deposits are distributed in the western and central segments of the Tianshan (i.e., the Western Tianshan) but not in Chinese Tianshan. Thus, the differences for metallogenesis of gold deposits between the Western and Chinese Tianshan attract intensive interest but remain ambiguous. Here we present sericite 40Ar/39Ar ages and S–Pb isotope compositions of pyrite from the Kanggur gold deposit, the largest shear zone-related gold deposit in the Chinese Tianshan. By integrating new sericite 40Ar/39Ar plateau ages (262.71 ± 2.95 Ma and 263.40 ± 2.94 Ma) with previous geochronological results, three peaks in gold mineralization are identified for the entire Tianshan: an early peak at ca. 330 Ma during which time subduction–accretion-related porphyry-type and orogenic gold deposits formed, a middle peak at ca. 290 Ma during which time post-collisional magmatism-related orogenic gold deposits formed in a collisional compressional to post-collisional extensional environment, and a late peak at ca. 260 Ma during which time strike–slip shear zone-related orogenic gold deposits formed in a post-collisional extensional environment. The sulfur (δ34SV-CDT of −1.0 to +2.5‰ for pyrite from ores and −1.9 to +2.6‰ for pyrite from wall rocks) and lead (18.199–18.231 for 206Pb/204Pb, 15.585–15.624 for 207Pb/204Pb, 38.104–38.229 for 208Pb/204Pb for pyrite from ores, and 18.176–18.244 for 206Pb/204Pb, 15.583–15.611 for 207Pb/204Pb, 38.090–38.205 for 208Pb/204Pb for pyrite from wall rocks) isotope compositions of pyrite indicate that the metals in gold deposits throughout the Tianshan were sourced from different reservoirs. In the Western Tianshan, the ore-forming metals for the deposits southwest of longitude 70°E were mainly sourced from upper crustal reservoirs, whereas those east of longitude 70°E were mainly sourced from lower crustal reservoirs. In the Chinese Tianshan, however, the ore-forming metals were dominantly sourced from lower crustal and/or mantle reservoirs. These different reservoirs were likely responsible for the distinct characteristics of the gold deposits located in the Western and Chinese Tianshan.

Efficient fullerene-free polymer solar cells (PSCs) are fabricated with a polymer donor PBDB-T1 and a non-fullerene acceptor ITTIC. With the incorporation of one thiophene bridge between the indacenodithienothiophene (IDTT) core and 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile (IC) terminal, the new acceptor ITTIC exhibits a higher lying lowest unoccupied molecular orbital (LUMO), and a narrower bandgap than the pristine ITIC acceptor. The resultant PSCs with PBDB-T1:ITTIC blends exhibit a power conversion efficiency of 9.12%, with an increased open circuit voltage (VOC) and broader photoresponse, compared with the PBDB-T1:ITIC based devices. Interestingly, it is shown that the charge transfer remains effective at a diminished highest occupied molecular orbital (HOMO) difference of 0.02 eV between PBDB-T1 and ITTIC, leading to a mitigated energy loss of 0.54 eV in PBDB-T1:ITTIC based devices. Overall, this work provides new insights into further improvement of fullerene-free PSCs.