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Charge carrier events across organic electronics are ubiquitous, and the derived optimization plays a crucial effect on improving the performance of organic electronics. Herein, a two-dimensional material (Ti

Herein, two simple furan-based polymers PFO3 and PFO4 grafting oligoethylene glycol (OEG) side chains are developed. PFO3 and PFO4 feature high hole mobility, large dielectric constant and good solubility. Compared to PFO4, PFO3 with shorter side chains demonstrates larger absorption coefficient and deeper electronic energy level. The air- and ethanol/water-processed OSCs based on PFO4:fullerene derivative (PCBO-12) show a modest efficiency of 2.06%. However, PFO3:PCBO-12 OSCs yield a higher efficiency of 3.03% due to the simultaneously enhanced photovoltaic parameters. PFO3- and PFO4-based devices remain 64.5% and 51.2% of their initial efficiency after continuous illumination for 200 h in inert atmosphere, respectively. Surprisingly, the remained efficiency ratio is increased to 81.6% and 69.1% for PFO3- and PFO4-based devices suffering from discontinuous illumination yet with the same soaking time of 200 h in inert atmosphere. However, the above phenomenon is not observed for other three photovoltaic systems without abundant OEG groups when adopting discontinuous illumination. The infrared spectroscopy and X-ray photoelectron spectroscopy unravel that the repaired efficiency of PFO3- or PFO4-based devices should be resulted from the self-healing of hydrogen bonds in photoactive layer. Our work will provide guidance for the future design of donor polymers for eco-friendly OSCs featuring high stability.

Ovarian injury caused by chemotherapy can lead to early menopause, infertility, and even premature senility in female cancer patients, impairing the quality of life and overall health of the cancer survivors seriously. However, there is still a lack of effective protection strategies against such injury. Cellular senescence can be induced by chemotherapeutic agents in multiple organs and may corrode the structure and function of normal tissues. We hypothesized that the widely used first-line chemotherapy drug, doxorubicin, could increase senescent cell burden in normal ovarian tissue during the therapeutic process and that elimination of senescent cells with senolytics would ameliorate doxorubicin-induced ovarian injury. Here, we demonstrated an accumulation of cellular senescence in doxorubicin-treated ovaries through detecting p16 and p21 expression levels and senescence-associated β-galactosidase (SA-β-gal) activity as well as senescence-associated secretory phenotype (SASP) factors. Short-term intervention with the classic senolytic combination dasatinib and quercetin (DQ) or fisetin significantly reduced the load of senescent cells in ovaries after doxorubicin treatment. However, neither DQ nor fisetin alleviated doxorubicin-related ovarian dysfunction. Further experiments showed that ovarian apoptosis and fibrosis following doxorubicin exposure could not be improved by senolytics. Collectively, our study shows that senolytic treatment can eliminate accumulated senescent cells, but cannot reverse the massive follicle loss and ovarian stromal fibrosis caused by doxorubicin, suggesting that cellular senescence may not be one of the key mechanisms in doxorubicin-induced ovarian injury.

Metal phosphates have shown good hydrogen evolution reaction catalytic ability, but as counter electrode (CE) materials they are rarely used in dye-sensitized solar cell (DSSC). A strategy that introduction of Co2P2O7 as a “collaborator” to improve the catalytic performance of Co4S3 for the DSSC. The Co4S3/Co2P2O7 film grew on carbon paper (CP) was synthesized by using a hydrothermal route and vapor deposition method, and served as platinum-free (Pt-free) CE for DSSC. The composite materials of Co4S3/Co2P2O7 has many advantages of unique spherical morphology, large special surface area, more active sites and fast reaction kinetics for the reduction of I−/I3−. Under optimal conditions, a DSSC based on the Co4S3/Co2P2O7/CP CE achieves a high power conversion efficiency of 8.99%, which is comparable to that of the Pt (7.49%) and CoS1.097/CP (8.18%) CEs. The results indicate that the Co4S3/Co2P2O7/CP CE with the advantages of efficient and facile synthesis is a promising alternative to the expensive Pt CE for the DSSCs in the future.

Exposure to anesthesia leads to extensive neurodegeneration and long-term cognitive deficits in the developing brain. Caenorhabditis elegans also shows persistent behavioral changes during development after exposure to anesthetics. Clinical and rodent studies have confirmed that altered expression of the regulators of G protein signaling (RGS) in the nervous system is a factor contributing to neurodegenerative and psychological diseases. Evidence from preclinical studies has suggested that RGS controls drug-induced plasticity, including morphine tolerance and addiction. This study aimed to observe the effect of propofol exposure in the neurodevelopmental stage on learning and memory in the L4 stage and to study whether this effect is related to changes in rgs-3 expression.Caenorhabditis elegans were exposed to propofol at the L1 stage, and learning and memory abilities were observed at the L4 stage. The expression of rgs-3 and the nuclear distribution of EGL-4 were determined to study the relevant mechanisms. Finally, RNA interference was performed on rgs-3-expressing cells after propofol exposure. Then, we observed their learning and memory abilities.Propofol time- and dose-dependently impaired the learning capacity. Propofol induced a decline in non-associative and associative long-term memory, rgs-3 upregulation, and a failure of nuclear accumulation of EGL-4/PKG in AWC neurons. Inhibition of rgs-3 could alleviate the propofol-induced changes.Inhibition of the expression of rgs-3 alleviated propofol-induced learning and memory deficits in Caenorhabditis elegans.

Designing efficient and economical dye-sensitized solar cells (DSSCs) free of precious metals is required to replace the platinum counter electrode (Pt CE) for further large-scale development. Here...

Perovskite solar cells (PSCs) have been regarded as an exceptional renewable energy conversion technology due to their rapidly increasing photovoltaic efficiency, while their practical application is highly retarded by their intrinsic instability and potential lead ion leakage. Here, a two-dimensional (2D) π-conjugated benzodifuran-based polymer, PBDFP-Bz, is adopted to modify the perovskite film. Note that PBDFP-Bz could neutralize surface defects, fine-tune interfacial energetics, and hamper moisture ingression into the perovskite film. Therefore, high-quality perovskite films featuring reduced trap state density and enhanced moisture tolerance could be obtained after modification via PBDFP-Bz. Consequently, PBDFP-Bz-modified devices deliver a higher efficiency of 21.73% versus 19.55% of control ones. Meanwhile, PBDFP-Bz-modified devices can preserve 82.7 and 90.8% of their initial efficiency under continuous heating at 85 °C or light soaking for 500 h. However, the corresponding retained values of control devices are only 56.4 and 70.2%, respectively. Moreover, PBDFP-Bz can effectively prevent the leakage of lead ions in modified devices relative to control ones. This work not only reveals that PBDFP-Bz features high potential for fabricating high-performance and robust PSCs but also indicates that 2D π-conjugated benzodifuran-based polymers can endow PSCs with great security for sustainable development without the concern of lead ion leakage.

Carbon-based all-inorganic CsPbI

Defect passivation management of perovskite films is of great importance in improving the performance of perovskite solar cells. Various in situ or post-passivation strategies were adopted to modify the optoelectric properties of perovskite films. However, these modifications increased the fabrication complexity and cost of the devices. Here, we developed a facile self-passivation strategy to effectively decrease charge trap states and suppress the non-radiative recombination loss in perovskite films. By simply aging the precursor solution, we found that the fabricated perovskite films possess residual PbI2 phase that could decrease trap density, enhance the radiative recombination intensity, and facilitate charge transfer and collection. Therefore, the solar cells with this self-passivated perovskite film generated an increased efficiency of 21.1% compared to that of 19.9% for the control devices from fresh precursor solution.

Organic solar cells (OSCs) simultaneously featuring good photovoltaic performance and strong humidity resistance are greatly anticipated for their practical application. Herein, we developed a simple organic trisiloxane molecule (denoted as TSi), and applied it to modify sol–gel ZnO (sg-ZnO) films. Compared to pristine sg-ZnO films, the TSi/sg-ZnO film presents fewer surface defects, shallower work function, and stronger hydrophobicity. Benefiting from those improved characteristics, when adopting a benzodifuran (BDF)-based polymer (BDFP-Bz) and Y6 as the electron donor and acceptor to fabricate OSCs, the derived devices utilizing TSi/sg-ZnO as the electron transport layer (ETL) showed suppressed charge recombination, enhanced charge extraction and increased stability to moisture versus the devices based on an sg-ZnO ETL. Meanwhile, PBDFP-Bz:Y6 OSCs based on a TSi/sg-ZnO ETL delivered a higher PCE of 14.62% than that of the control devices (12.39%). More importantly, the TSi/sg-ZnO ETL was also applicable in other different photovoltaic systems, among which PM6:Y6 OSCs based on a TSi/sg-ZnO ETL yielded a superior PCE of 16.37% along with stronger stability to moisture versus the reference ones. Our finding demonstrates the TSi/sg-ZnO bilayer ETL holds promise in the practical application of OSCs for simultaneously improving the photovoltaic performance and moisture-resistance of devices.

Lead-free metal halide perovskites have attracted extensive attention as promising optoelectronic semiconductors with environmental friendliness. Cs2SnI6, a double perovskite with both a good phase and composition stability, is an appealing candidate for potential application in optoelectronic devices. To date, few reports have focused on the facile fabrication of dense and uniform Cs2SnI6 films that are key components for optoelectronic devices. Herein, a simple and low-cost solution method is reported to prepare densely packed Cs2SnI6 thin films. It was found that strategic precursor-compensation treatment (PCT) of the as-prepared spin-coated Cs2SnI6 thin films compensates the evaporation loss of volatile SnI4 and thus allows for pinhole-free and pure-phase double perovskite. The modified n-type Cs2SnI6 double perovskite shows enhanced conductivity and mobility with decreased charge recombination loss. As a result, the applied photodetectors show an enhanced photocurrent gain of 151 compared to that of 88 for the control sample. The responsivity (control 0.0059 mA W−1 to target 1.07 mA W−1) and detectivity (control 2.94 × 1010 Jones to target 6.03 × 1010 Jones) of the device were significantly improved in the self-powered mode. In addition, the PCT-Cs2SnI6 photodetectors show excellent long-time stability with 98% initial detectivity retained after storing in ambient environment for 28 days. This study paves the way for the preparation of high-quality Cs2SnI6 films for application in efficient optoelectronic devices.

Transition metal phosphates have aroused wide attention and been applied in the field of energy conversion due to their high catalytic properties and low cost, but magnetic metal phosphates are rarely used in DSSC. In this work, the magnetic CoP@FeP4 thin film was prepared on carbon paper (CP) using a two-step process and proposed as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). The morphology of CoP@FeP4@CP with a silkworm-like structure is advantageous to enhance the catalytic ability for the interface reaction, establish a good connection between the electrode material and electrolyte, and accelerate the electron transmission. The characterizations using cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel curves all indicate that the CoP@FeP4@CP CE shows excellent electrochemical catalytic performance for the I−/I3− electrolyte. Under optimal conditions, a high power conversion efficiency of 9.88% is achieved for DSSC with CoP@FeP4@CP CE much higher than that of Pt (7.49%) and CoP@CP (8.73%) CEs. This phenomenon can be attributed to the unique chemical structure and the synergistic effect of CoP@FeP4@CP CE. CoP@FeP4@CP CE with the advantages of efficient, low cost, and facile synthesis is a promising alternative to the expensive Pt CE for the DSSCs in the future.

The cobalt triphosphide (CoP3) was grew on carbon paper (CP) by using a hydrothermal method and served as counter electrode (CE) catalyst in dye-sensitized solar cells (DSSCs). The morphology of the CoP3/CP CE exhibits a regular fibrous structure, which provides a guarantee for its good electrochemical performance of the CE made from the cyclic voltammetry, Tafel test, etc. Various photoelectric performance tests also show that the DSSCs with CoP3/CP CE achieves good photoelectric conversion efficiency of 6.84% under 100 mW·cm−2 illumination, which can compare to that of the DSSC assembled with the Pt (6.79%) CE. Metal phosphides are rarely used as CEs in DSSCs, and they will have a good promising alternative to the Pt electrode in the future.

A petal-like MoIn2S4 thin film with excellent performance was synthesized on conductive fluorine-doped tin oxide (FTO) substrate through the hydrothermal method. The MoIn2S4 thin film with 0.169 g InCl3 exhibited the most excellent electrocatalytic activity and lowest charge transfer resistance of 19.90 Ω cm−1 among the various MoIn2S4 samples in I−/I3− redox couple, which was confirmed through a series of electrochemical investigations. The photoelectric conversion efficiency for the DSSC served the MoIn2S4 thin film as counter electrode achieved 6.51% under 100 mW·cm−2 illumination, which was a little better than that of the DSSC assembled with the Pt (6.39%) electrode. This research demonstrates that the petal-like MoIn2S4 counter electrode with simple preparation process, excellent electrocatalytic activity and efficient photoelectric conversion efficiency is a promising alternative to the conventional Pt electrode in DSSCs.

Ovarian damage induced by platinum-based chemotherapy seriously affects young women with cancer, manifesting as infertility, early menopause, and premature ovarian insufficiency. However, effective prevention strategies for such damage are lacking. Senescent cells may be induced by chemotherapeutic agents. We hypothesized that cisplatin can lead to senescence in ovarian cells during the therapeutic process, and senolytic drugs can protect animals against cisplatin-induced ovarian injury. Here, we demonstrated the existence of senescent cells in cisplatin-treated ovaries, identified the senescence-associated secretory phenotype, and observed significant improvement of ovarian function by treatment with metformin or dasatinib and quercetin (DQ) independently or in combination. These senotherapies improved both oocyte quality and fertility, increased the ovarian reserve, and enhanced hormone secretion in cisplatin-exposed mice. Additionally, attenuated fibrosis, reorganized subcellular structure, and mitigated DNA damage were observed in the ovaries of senotherapeutic mice. Moreover, RNA sequencing analysis revealed upregulation of the proliferation-related genes Ki, Prrx2, Sfrp4, and Megfl0; and the antioxidative gene H2-Q10 after metformin plus DQ treatment. Gene ontology analysis further revealed that combining senotherapies enhanced ovarian cell differentiation, development, and communication. In this study, we demonstrated that metformin plus DQ recovered ovarian function to a greater extent compared to metformin or DQ independently, with more follicular reserve, increased pups per litter, and reduced DNA damage. Collectively, our work indicates that senotherapies might prevent cisplatin-induced ovarian injury by removing senescent cells and reducing DNA damage, which represent a promising therapeutic avenue to prevent chemotherapy-induced ovarian damage.

Fused-ring electron donors boost the efficiency of organic solar cells (OSCs), but they suffer from high cost and low yield for their large synthetic complexity (SC > 30%). Herein, the authors develop a series of simple non-fused-ring electron donors, PF1 and PF2, which alternately consist of furan-3-carboxylate and 2,2'-bithiophene. Note that PF1 and PF2 present very small SC of 9.7% for their inexpensive raw materials, facile synthesis, and high synthetic yield. Compared to their all-thiophene-backbone counterpart PT-E, two new polymers feature larger conjugated plane, resulting in higher hole mobility for them, especially a value up to ≈10-4 cm2 V-1 ·s for PF2 with longer alkyl side chain. Meanwhile, PF1 and PF2 exhibit larger dielectric constant and deeper electronic energy level versus PT-E. Benefiting from the better physicochemical properties, the efficiencies of PF1- and PF2-based devices are improved by ≈16.7% and ≈71.3% relative to that PT-E-based devices, respectively. Furthermore, the optimized PF2-based devices with introducing PC71 BM as the third component deliver a higher efficiency of 12.40%. The work not only indicates that furan-3-carboxylate is a simple yet efficient building block for constructing non-fused-ring polymers but also provides a promising electron donor PF2 for the low-cost production of OSCs.

Nitrogen/phosphorus-doped carbon dots (N, P-CDs) with a quantum yield as high as 76.5% were synthesized by carbonizing maize starch via a facile ethanol solvothermal approach. Transmission electron microscopy (TEM) measurement shows that the as-prepared N, P-CDs displayed a quasi-spherical shape with a mean size of ca. 2.5 nm. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy disclosed the presence of –OH, –NH2, –COOH, and –CO functional groups over the surface of N, P-CDs. On the basis of excellent fluorescent properties with strong blue fluorescence emission at 445 nm upon excitation at 340 nm, these N, P-CDs were adopted as a fluorescent probe towards the effective detection of Fe3+ ions in water. The limit of detection (LOD) was as low as 0.1 μmol L−1 and showed a better linear relationship in the range of 0.1 ∼ 50 μmol L−1. In conclusion, these synthesized N, P-CDs can be efficiently used as a promising candidate for the detection of Fe3+ ions in some practical samples.

Hydrogen evolution reaction (HER) is one of the key components for the hydrogen-centered renewable clean energy system. Developing efficient HER electrocatalysts that make use of earth-abundant elements is highly desirable yet challenging. Herein, we report a three-dimensional (3-D) CoP3 nanoplate arrays in situ grown on carbon cloth (CoP3 NPAs/CC), which is synthesized by a facile topotactic phosphidation method under hydrothermal condition. As a HER electrocatalyst, the as-prepared CoP3 NPAs/CC exhibit great catalytic activity that is comparable to Pt, over a large pH range of 0–14. At pH = 0, such flexible and efficient CoP3 electrocatalysts can deliver a high current density of 100 mA cm−2 at an overpotential as low as 113 mV, with no apparent activity loss over 40 h. By theoretical calculation and experimental measurements, the outstanding HER performance of the CoP3 NPAs/CC can be attributed to the good conductivity property, synergistic effect between Co and P, unique rich-phosphorous CoP3 nanoplate arrays structure and the great intrinsic catalytic activity. As a highly efficient HER catalyst, CoP3 NPA offers a promising alternative of non-PGM catalysts for electrochemical hydrogen production.

Two benzodifuran (BDF) polymers, PBDF-C and PBDF-S, with alkyl and alkylthio substituted thiophene side-chains and benzodithiophene-4,8-dione (BDD) as the acceptor were designed and synthesized. Their optical, electrochemical properties and photovoltaic performances were systematically investigated. The polymer solar cells (PSCs) with a device structure of ITO/PEDOT:PSS/polymer:PC71BM/Ca/Al were fabricated. The PBDF-C based device showed a power conversion efficiency (PCE) of 3.01% after adding 1 vol% 1,8-diodooctane (DIO) as the solvent additive, and PBDF-S gave an enhanced PCE of 3.48% without any post-treatments. The enhancements were from the higher open-circuit voltage (Voc) and fill factor (FF). The thermal- and solvent-treatment-free processing is more favourable for the large area roll-to-roll manufacturing or printing technology for PSCs.

In this work, a novel starch phosphate carbamate hydrogel (SPC-Hydrogel) and its corresponding urea hydrogel (SPCU-Hydrogel) slow-release fertilizer (SRF) were prepared by one-step free radical copolymerization of SPC and acrylamide (AM) without and with urea addition. A series of characterization measurements including FTIR, XRD, EDS, XPS are utilized to confirm the successful formation of the SPC-Hydrogel. The SEM shows SPC-Hydrogel has a porous three-dimensional network architecture. Furthermore, SPC-Hydrogel matrix exhibits superior water absorbency achieving 80.2 g/g than that (70.5 g/g) of the native starch hydrogel (NS-Hydrogel) and desirable water retention capacity in soil with a weight loss of only 48% for 13 days. Compared with pure urea and NS based urea hydrogel (NSU-Hydrogel), the SPCU-Hydrogel releases 50.3% for 15 h, achieving an almost complete release more than 25 h in aqueous phase. While only 46.6% of urea is released in 20 days which extends about 30 days in soil column assays. The maize seedlings growth assays also present an intuitive evaluation on the prominent soil water holding and plant growth promotion role of SPCU-Hydrogel. In conclusion, the present work has demonstrated a novel strategy via preparing biomass hydrogel SRF to enhance the utilization effectiveness of fertilizer and retain soil humidity.

Nitrogen/phosphorus-doped carbon dots (N, P-CDs) with a quantum yield as high as 76.5% were synthesized by carbonizing maize starch

In this work, a kind of boron doped carbon spheres (B-CSs) was successfully synthesized utilizing maize starch as carbon source and boric acid as dopant via facile solvothermal method. The chemical structure of the prepared B-CSs was systemically investigated by TEM, FT-IR, XRD, XPS and EDS. The synthesized B-CSs feature spherical structure with average size of ∼254 nm and exhibit strong photoluminescence (PL) with maximum emission at a wavelength of ∼453 nm under irradiation at 350 nm, leading to a quantum yield of 6.2%. Furthermore, the aqueous pH and Cr(VI) has a significantly various impact on the PL intensity of B-CSs, which can be flexibly utilized as the PL sensor for detection aqueous pH and Cr(VI) in aqueous. Particularly, the B-CSs have a desirable sensitivity and selectivity for detection of Cr(VI) with a low detection limit of ∼0.34 μmol l−1. Conclusively, our work provides a novel and dual-functional fluorescent sensor for detection of the pH and toxic metal ions in water environment.

Dye-sensitized solar cells (DSSCs) with TiO2 as electron transport layer (ETL) demonstrate great potential in the field of photoelectric devices featuring low cost and high power conversion efficiency (PCE). However, the photovoltaic performance of DSSCs based on TiO2 ETL is still confined by the undesirable charge recombination occurring in TiO2 layer (intrinsic defects), dye layer (self-quenching) and at the interface between TiO2 and electrolyte (back electron transfer). Herein, we firstly adopted a trisiloxane molecule (denoted as TSi) to holistically reduce the abovementioned charge recombination of DSSCs via passivating surface defects of TiO2, fine-tuning dye molecules arrangement and forming interfacial energy barrier. As a result, the Z907-based DSSCs with TiO2/TSi ETL deliver a high PCE of 9.43%, increasing over 16% than that of DSSCs without TSi treatment. Meanwhile, the DSSCs based on TiO2/TSi ETL present stronger endurance to high humidity and better long-term stability versus that of the DSSCs without TSi treatment. Our work provides a simple yet effective strategy to holistically reduce charge recombination of devices for improving the photovoltaic performance and stability of DSSCs.

Two novel narrow bandgap copolymers PIDTFPQ and PIDTFTQ based on bulky indacenodithiophene (IDT) and mono-fluorophenanthrenequinoxaline (FPQ) or mono-fluorodithienobenzoquinoxaline (FTQ), which possess a large fused phenanthrene or benzodithiophene ring on top of pyrazine unit, are designed and synthesized. The optical properties, electrochemical properties, π-π packing behavior, charge carrier transport, morphology and photovoltaic properties of two copolymers were thoroughly investigated via a series of techniques. Owing to the smaller volume of dithienobenzoquinoxaline, PIDTFTQ shows more planar structure. Furthermore, PIDTFTQ presents slightly red-shifted onset absorption and denser π-π stacking. Besides, PIDTFTQ:PC71BM blend film displays higher hole and electron mobilities of 1.46 × 10−4 cm2V−1s−1 and 2.64 × 10−4 cm2V−1s−1 than those of PIDTFPQ/PC71BM blend film. More excitingly, without using any additives or any thermal/solvent annealing, the polymer solar cells based on PIDTFTQ/PC71BM and PIDTFPQ/PC71BM obtained higher Voc of 0.92 V and 0.93 V and promising PCE of 5.54% and 5.00%, respectively. The results show that PIDTFTQ or PIDTFPQ possess a great potential for large area roll-to-roll manufacturing or printing technology for PSCs.

A novel conjugated D–A polymer, PTBFBz, with asymmetrical thieno[2,3-f]benzofuran (TBF) and fluorobenzotriazole (Bz) units was designed and synthesized for the first time. PTBFBz showed the strong absorption with a wide bandgap of 1.89 eV. Power conversion efficiency of nonfullerene polymer solar cells based on PTBFBz:ITIC with thermal and sequential solvent annealing reached up to 8.33%, which is the highest reported value among the asymmetrical TBF-based polymer solar cells. The results demonstrate that the asymmetrical TBF unit can be one of the most promising building blocks in constructing the wide bandgap polymers for highly efficient polymer solar cells.

Wide bandgap conjugated polymers are important for providing complementary absorption with the state-of-the-art narrow bandgap nonfullerene electron acceptors to maximise the utilization of solar photons. In this work, two wide bandgap two-dimensional conjugated polymers, PBDFT–Bz and PBDFF–Bz, based on benzo[1,2-b:4,5-b′]difuran building block were designed and synthesized. The optical bandgaps of PBDFT–Bz and PBDFF–Bz were found to be 1.90 eV and 1.85 eV, respectively. PBDFF–Bz with 2-ethylhexylfuryl side chains possesses the lower HOMO energy level and shows denser π–π stacking compared to PBDFT–Bz with 2-ethylhexylthienyl side chains. The fullerene-free PBDFF–Bz:ITIC-based polymer solar cell (PSC) showed a PCE of 9.46% with a Jsc of 15.02 mA cm−2, a Voc of 0.94 V and a FF of 67%; by using m-ITIC as an electron acceptor, the PCE was further improved to 10.28% with an enhanced Jsc of 16.57 mA cm−2, a Voc of 0.94 V and a FF of 66%. Under the same condition, the PBDFT–Bz:m-ITIC device gave a PCE of 9.84% with a Jsc of 16.63 mA cm−2, a Voc of 0.85 V and a FF of 70%. In addition, it is exciting that the PBDFF–Bz based devices show a small energy loss (Eloss) of 0.63 eV, while the PBDFT–Bz based devices show an Eloss of 0.72 eV. These results are among the best for fullerene-free devices with BDF-based polymers, and demonstrate that BDF is a very promising candidate for highly efficient polymer solar cells.

A new donor-acceptor type conjugated polymer (PTBFTPD) based on two-dimensional (2D) conjugated alkylthienyl substituted thieno[2,3-f]benzofuran (TBF) and thienopyrroledione (TPD) unit, was synthesized and applied as donor material for bulk heterojunction polymer solar cells. As a comparison, its counterpart conjugated polymer (PBDTTPD) based on alkylthienyl substituted thieno[2,3-f]benzothiophene (BDT) and TPD unit, was also synthesized. The thermal properties, optical and electrochemical properties, energy levels, molecular chain orientation stacking behavior and photovoltaic properties of two polymers were intensively investigated. Both polymers showed similar optical properties. Compared with PBDTTPD, PTBFTPD shown the similar absorption properties in solution and in a thin film. PTBFTPD had a slightly narrow bandgap of 1.83 eV while that of 1.85 eV for PBDTTPD. PTBFTPD displayed a deeper highest occupied molecular orbital (HOMO) energy level of (−5.64 eV), which was 0.1 eV lower than that for PBDTTPD. The XRD study showed that PTBFTPD possessed a closer π-π stacking than PBDTTPD. The photovoltaic properties were investigated under various conditions, the optimized power conversion efficiency (PCE) of 4.33% with an open-circuit voltage (Voc) of as high as 1.09 V were obtained, which resulted in a 32% improvement in comparison with PBDTTPD/PC71BM-based device under the same conditions.

Two novel benzo[1,2-b:4,5-b' ]difuran (BDF)-based wide-bandgap polymers, PBDFT-FBz and PBDFF-FBz, featuring a difluorobenzotriazole (FBz) acceptor unit, are designed and synthesized. The first attempt through main-chain engineering to alter thiophene units to furan units in the main chain of PBDFT-FBz, and further side-chain engineering eliminate the 2-ethylthiophenyl side chains of PBDFT-FBz by 2-ethylfuryl side chains to generate the "all-furan" polymer PBDFF-FBz. By taking the benefit of the oxygen atom in furan, both PBDFT-FBz and PBDFF-FBz exhibit lower HOMO energy levels and enhanced polymer chain interactions compared to their benzo[1,2-b:4,5-b' ]dithiophene (BDT)-based counterparts. As a result, while applying both polymers in non-fullerene polymer solar cells with non-fullerene acceptor m-ITIC, both devices exhibit highly promising photovoltaic performance. The power conversion efficiency (PCE) in the PBDFT-FBz device reaches 7.57% with increased open circuit voltage (Voc ) and fill factor (FF) compared to the PCE of 5.98% in its BDT counterpart (J52). A further increased PCE is obtained (8.79%) in the PBDFF-FBz:m-ITIC device, which shows ≈47% enhancement in device performance compared to that of J52. The large increase in photovoltaic performance is attributed to the lower-lying HOMO energy levels and better chain interactions in these BDF-based polymers.

A new ethanol soluble all-furan based copolymer (PFF) was firstly designed and synthesized. PFF exhibits strong absorption in the range of 300-700 nm, and presents a highest occupied molecular orbital energy level of – 5.21 eV. The organic photovoltaics based on PFF: PCBO-12 display a low power conversion efficiency (PCE) of 0.49% when fabricated with ethanol. Interestingly, the PCE would be improved to 0.66% along with simultaneous enhancement of all photovoltaic parameters for devices by applying 1.5% p-anisaldehyde additive. The experiment analysis indicates the low PCE of the optimized device is ascribed to severe phase segregation and the large surface roughness of the active layer, which were verified by the TEM and AFM characterization.