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Two dimensional Dion-Jacobson (2D DJ) perovskite has emerged as a potential photovoltaic material because of its unique optoelectronic characteristics. However, due to its low structural flexibility and high formation energy, extra assistance is needed during crystallization. Herein, we study the solvent effect on film formation and trap states of 2D DJ perovskite. It is found that the nucleation process of 2D DJ perovskite can be retarded by extra coordination, which is proved by in situ optical spectra. As a benefit, out-of-plane oriented crystallization and ordered phase distribution are realized. Finally, in 1,5-pentanediammonium (PeDA) based 2D DJ perovskite solar cells (PSCs), one of the highest reported open-circuit voltage (

N(6)-methyladenosine (m6A)-modified microRNAs (miRNAs) are relevant to cancer progression. Also, although the involvement of miR-380-3p in regulating cancer progression in bladder cancer and neuroblastoma has been preliminarily explored, its role in other types of cancer, such as pancreatic cancer (PC), has not been studied. Thus, this study aimed to investigate the role of miR-380-3p in regulating PC progression. Here, through performing Real-Time qPCR, we evidenced that miR-380-3p was significantly upregulated in the clinical pancreatic cancer tissues and cells compared to their normal counterparts. Interestingly, miR-380-3p was enriched with m6A modifications, and elimination of m6A modifications by deleting METTL3 and METTL14 synergistically suppressed miR-380-3p expressions in PC cells. Next, the gain and loss-of-function experiments verified that knockdown of miR-380-3p suppressed cell proliferation, epithelial-mesenchymal transition (EMT), and tumorigenesis in PC cells

Siloxane with low surface tension can regulate the intermolecular interactions, and optimize the phase separation morphology and molecule stacking, finally contributing to an excellent PCE of 16.4% with small energy loss for ASM-OSCs.

Summary Surface energy of the underneath interlayer plays a crucial role in determining the morphology of bulk-heterojunction (BHJ) film in solution-processed organic solar cells (OSCs). However, little attention has been paid to this perspective at the microscopic level. In this study, we demonstrate an effective strategy to tune the nanoscale heterogeneous distribution of surface energy (HeD-SE) at interlayers through incorporating two-dimensional (2D) MoS2 nanosheets, which modulate the component distribution, molecular orientation, and phase separation in the upper BHJ layers, leading to suppressed charge recombination and increased charge extraction in devices with enhanced power conversion efficiency (PCE) and device stability. Furthermore, we explore the relationship among the different surface energies of BHJs between the donor and the acceptor, the nanoscale HeD-SE at interlayers, and the PCEs of the resultant devices. This work reveals the impact of nanoscale heterogeneity in the distribution of surface energy in the underneath interlayers on the BHJ morphology and device performance in OSCs.

With nearly 100% yields for mobile charge carriers in organic solar cells (OSCs), the relatively large photovoltage loss (ΔVoc) is a critical barrier limiting the power conversion efficiency of OSCs. Herein, we aim to improve the open-circuit voltage (Voc) in OSCs with non-fullerene acceptors via sequential film deposition (SD). We show that ΔVoc in planar heterojunction (PHJ) devices prepared by the SD method can be appreciably mitigated, leading increases in Voc to 80 mV with regard to the Voc of bulk heterojunction devices. In PHJ OSCs, the energy level of intermolecular charge-transfer states is found to increase with a decrease in the level of aggregation in the solid state. These properties explain the enhanced electroluminescent quantum efficiency and resultant suppression of the voltage losses induced by nonradiative charge recombination and interfacial charge transfer. This work provides a promising strategy for tackling the heavily discussed photovoltage loss in OSCs.

Quasi-2D Ruddlesden-Popper (RP) perovskites with superior stability are admirable candidates for perovskite solar cells (PSCs) toward commercialization. However, the device performance remains unsatisfactory due to the disordered crystallization of perovskites. In this work, the effects of sulfonium cations on the evolution of intermediates and photovoltaic properties of 2D RP perovskites are investigated. The introduction of sulfonium cations leads to preferred intermediate transformation and improved film quality of perovskites. The resulting devices deliver a champion efficiency of 19.08% at room temperature and 20.52% at 180 K, due to reduced recombination and enhanced charge transport. More importantly, the unencapsulated device maintains 84% of the initial efficiency under maximum power point (MPP) tracking at 40 °C for 1000 h. This work helps to gain a comprehensive understanding of the crystallization process of quasi-2D perovskites and provides a simple strategy to modulate the intermediates of perovskites.

Although the photovoltaic performance of perovskite solar cells (PSCs) has reached the commercial standards, the unsatisfactory stability limits their further application. Hydrophobic interface and encapsulation can block the damage of water and oxygen, while the instability induced by intrinsic residual strain remains inevitable. Here, the residual strain in a two-dimensional (2D) Ruddlesden-Popper (RP) perovskite film is investigated by X-ray diffraction and atomic force microscopy. It's found that the spacer cations contribute to the residual strain even though they are not in the inorganic cages. Benefited from strain relaxation, the film quality is improved, leading to suppressed recombination, promoted charge transport and enhanced efficiency. More significantly, the strain-released devices maintain 86 % of the initial efficiency after being kept in air with 85 % relative humidity (RH) for 1080 h, 82 % under maximum power point (MPP) tracking at 50 °C for 804 h and 86 % after continuous heating at 85 °C for 1080 h.

Experimental determination of equilibrium solubility of 1-(2-bromophenyl)-pyrrole-2,5-dione in binary aqueous solutions containing a co-solvent of isopropanol, ethanol, N-methyl-2-pyrrolidinone (NM...

Summary Two-dimensional (2D) perovskites with excellent stability and optoelectronic properties have aroused great interest for use in perovskite solar cells (PSCs). To date, the power conversion efficiencies (PCEs) of state-of-the art 2D-PSCs are non-satisfactory because of higher recombination losses in 2D quantum wells. Here, based on a series of alkylic ammonium spacers (ethylamine to hexylamine) with different chain lengths, we present a strategy via the molecular van der Waals interaction to realize modified crystallization, phase distribution, and quantum-confined behaviors in Ruddlesden-Popper 2D perovskites (n = 4). With the optimal amylamine (AA) spacer, high-quality 2D perovskites featuring well-aligned phase alignments with fewer unfavorable n-value species and a reduced exciton binding energy have been realized, leading to sufficient charge transfers through different n-value components. The devices based on (AA)2MA3Pb4I13 yield a champion PCE of 18.42%, showing an impressive open-circuit voltage of 1.25 V and a fill factor exceeding 0.80.

In comparison to widely adopted bulk heterojunction (BHJ) structures for organic solar cells (OSC), exploiting the sequential deposition to form planar heterojunction (PHJ) structures enables to realize the favorable vertical phase separation to facilitate charge extraction and reduce charge recombination in OSCs. However, effective tunings on the power conversion efficiency (PCE) in PHJ-OSCs are still restrained by the currently available methods. Based on a polymeric donor PBDBT-2F (PBDBT= Poly [[4,8-bis [5-(2-ethylhexyl)-4-fluoro-2-thienyl]benzo [1,2- b :4,5- b ′]dithiophene-2,6-diyl]-2,5-thiophenediyl [5,7-bis (2-ethylhexyl)-4,8-dioxo-4 H ,8 H -benzo [1,2- c :4,5- c ′]dithiophene-1,3-diyl]-2,5-thiophenediyl]) and a non-fullerene (NF) acceptor Y6, we proposed a strategy to improve the properties of photovoltaic performances in PHJ-based OSCs through dilute dispersions of the PBDBT-2F donor into the acceptor-dominant phase with the sequential film deposition. With the control of donor dispersions, the charge transport balance in the PHJ-OSCs is improved, leading to the expedited photocarrier sweep-out with reduced bimolecular charge recombination. As a result, a PCE of 15.4% is achieved in the PHJ-OSCs. Importantly, the PHJ solar cells with donor dispersions exhibit better thermal stability than corresponding BHJ devices, which is related to the better film morphology robustness and less affected charge sweep-out during the thermal aging.

A simple-structure zwitterion of sulfamic acid (+H3N–SO3–, SA) is introduced to construct an effective chemical bridge between SnO2 and a perovskite layer through a coordination bond via the -SO3– anion for remedying the oxygen vacancies of SnO2 and meanwhile to passivate charged defects of the perovskite through electrostatic interaction via the -NH3+ cation. The introduced SA results in high-quality perovskite films with large grain size, due to the better wettability for perovskite solution. Consequently, the SA-modified solar cell generates an enhanced efficiency from 18.2% to 20.4% with negligible hysteresis. Remarkably, the unsealed device with SA modification also exhibits considerably improved stability.

Bromine-containing metal halide all-inorganic perovskite CsPbI2Br exhibits excellent photoelectric performance and supreme thermal and structural stabilities; it is thus attractive for use as photoabsorbing layers in perovskite solar cells (PSCs). However, when steric hindrance molecules are introduced, the complicated phase transition mechanism and the difficult-to-control crystallization process in CsPbI2Br are not well understood. Here, we introduce a class of sterically hindered cesium naphthenate small molecules to control the crystallization process of CsPbI2Br films. Of interest, a new intermediate monoclinic phase has been discovered which leads to formation of dense and nonporous polycrystalline perovskite films. This phenomenon was also explained by density functional theory. The residues of steric hindrance molecules inside the CsPbI2Br film also improve its stability. We further show that as the ring number of cycloalkanes increases, the hindrance for the crystallization becomes more significant. Thus, by choosing the suitable steric hindrance, the optimal photovoltaic efficiency is 15.45%.

Ligand exchanges play a crucial role in development of high-quality colloidal quantum dot (CQD) solids for fast and sensitive short-wavelength infrared photodetection. Sargent et al. report a two-step ligand exchange route to tailor efficient passivation, remove unwanted organics, and enhance charge transport, leading to a CQD photodetector with an EQE > 80% at 1550 nm, a measured detectivity of 8 × 1011 Jones, and a 10-ns response time.

The performance of organic solar cells (OSCs) depends on a fine, carefully optimized bulk-heterojunction (BHJ) microstructure. The understanding and manipulation of BHJ morphology have been the focus of research in optoelectronic devices. In this article, recent advances in understanding and controlling the BHJ morphology via substrate engineering and BHJ active layer processing are reviewed. From the chemical and physical surface structure of substrates, we reviewed the active layer morphology depending on the nature of the substrate and the deposition conditions, and it can also be controlled to change the blend-substrate interface by changing the surface properties of the substrate. We also reviewed the effect of solvent (co-solvent and solvent additive) and post-treatment (thermal annealing and solvent vapor annealing) on the evolution kinetics of the film, which helps to form the optimal percolation path and thus provides a simple way to improve photovoltaic performance. Since the interaction between intermolecules is weak, the sensitive assembly of molecules depends on fining miscibility between the components in the BHJ active layer. Starting from the processing conditions of the substrate and the active layer can greatly control the morphology of BHJ, and provide future research directions for OSCs.

Herein, a new electropolymerized (EP) film named poly-triphenylcarbazole fluoranthene (p-TPCF) has been in situ synthesized by an electrochemical cyclic voltammetry method and applied to tune the work-function (WF) of the PEDOT:PSS hole-transporting layer (HTL) in organic solar cells (OSCs). Multiple techniques, including Kelvin probe force microscopy (KPFM), light intensity dependent solar cell characterization, Mott–Schottky analysis, and transient photovoltage (TPV) and transient photocurrent (TPC) measurements, have been explored to provide insights into the mechanism. Benefiting from the deeper work-function (WF), larger built-in voltage (Vbi), decreased recombination, and longer carrier lifetime, the devices with EP films exhibited superior device performance with simultaneously enhanced Voc, Jsc and FF.

The solubilities of 1-(2-bromo-phenyl)-pyrrole-2,5-dione in 14 pure solvents including isopropanol, methanol, isobutanol, ethanol, n-propanol, n-butanol, ethylene glycol (EG), cyclohexane, acetone,...

Background MicroRNA (miR)-21 is overexpressed in numerous types of malignancy and participates in the development of cancer. However, the basic mechanism of the influence of miR-21 on the malignant phenotype of pancreatic cancer remains unclear. Purpose The present study aimed to investigate the role of miR-21 in pancreatic cancer development and explore its molecular mechanism. Patients and methods The tissue samples were collected at the Second Hospital of Tianjin Medical University (Tianjin, China) between January 2013 and December 2015. The expression of VHL in tissue samples was evaluated by IHC staining. The expression of miR-21 was measured by quantitative real-time polymerase chain reaction (qRT-PCR). MiR-21 target gene was detected by real-time PCR, Western blot and the luciferase reporter assay. Cell viability, cell proliferation, cell migration and invasion were evaluated by the MTT assays, the colony formation assays and the transwell assays. The nude mouse tumor xenograft model was performed to detect the effect of miR-21 on tumor growth in vivo. Results Von Hippel-Lindau tumor suppressor (VHL) was downregulated in pancreatic cancer tissues compared with pancreatic non-tumor tissues. VHL was identified as a novel direct target of miR-21, by which it is negatively regulated. In PANC-1 cells, inhibition of miR-21 and upregulation of VHL significantly suppressed cell proliferation, migration and invasion. Knockdown of miR-21 inhibited the hypoxia-inducible factor (HIF)-1α/vascular endothelial growth factor (VEGF) pathway, while inhibiting the expression of matrix metallopeptidase (MMP)-2 and MMP-9. Silencing of miR-21 inhibited tumor growth in vivo. Conclusion Knockdown miR-21 increased the expression of VHL, and thus modulated the HIF-1α/VEGF pathway and the expression of MMP-2 and MMP-9, which led to the inhibition of the proliferation, migration and invasion of pancreatic cancer cells. All of these results suggest that the miR-21/VHL interaction may be a novel potential target for pancreatic cancer prevention and therapy.

SUMMARYThe fill factor (FF) of organic solar cells (OSC), a critically important photovoltaic parameter, is yet sub-optimal, often less than 0.8. To further reduce the FF gaps with regard to the Shockley-Queisser upper limit, we present a study unveiling the impacts of dielectric properties on obtaining high FFs and photovoltaic efficiencies in OSCs. With increasing the dielectric constant (e) of non-fullerene acceptors (NFAs) and bulk heterojunction (BHJ) films, afforded by the increase of molecular packing density (MPD) of NFAs in solid states, we show that the FF penalties related to non-geminate charge recombination in OSCs can be appreciably mitigated. This conceptual modulation on FFs is embodied by a series of NFA-based BHJs where the differentiated MPDs and resultant changes of e in BHJs are reflected by the difference in FFs. In particular, as exemplified by an NFA model system L8-BO tailored with branched side chains, the enlargements of MPD and e allow to achieve an impressive FF of 0.815 with efficiency of 18.23% in OSCs featuring an impressively low bimolecular recombination and reduced sensitivity of FF on the BHJ film thickness.

The cathode interlayer plays a key role in the photovoltaic performance in organic solar cells. In this work, we demonstrate that polydopamine/ZnO can be used as efficient electron transport layers (ETL) in inverted non-fullerene organic solar cells. In comparison to the devices with the ZnO ETL, the power conversion efficiency of inverted PBDBT:ITIC solar cells with the PDA/ZnO ETL can be boosted from 10.15% to 11.14%, due to the simultaneously enhanced open-circuit voltage, short-circuit current and fill factor. The increased photovoltaic performance is mainly attributed to a faster charge extraction ability at the cathode interface and longer carrier lifetime, confirmed by transient optoelectrical analyses. Revealed by conductive-AFM and KPFM coupled with absorption spectroscopy, high optical transmittance and vertical electrical conductivity with a suitable low work function and a doping effect induced by PDA were observed in the PDA modified ZnO, which makes it a good ETL material for inverted solar cells and indicated universal applicability. This work provides a new approach to modify the cathode interfacial properties towards high efficiency organic solar cells with non-fullerene acceptors.

A laser monitoring method was used to determine the mole-fraction solubility of naphazoline nitrate (NPZN) in ten mono-solvents namely “methanol (MeOH), ethylene glycol monomethyl ether (EGME), ethanol (EtOH), ethylene glycol monoethyl ether (EGEE), n-propanol (n-PrOH), ethylene glycol monopropyl ether (EGPE), isopropanol (i-PrOH), ethylene glycol (EG), ethylene glycol monobutyl ether (EGBE) and N,N-dimethylformamide (DMF)” at (278.15 ∼ 323.15) K and 0.1 MPa. Results suggested that NPZN solubility values exhibited an increasing trend at investigated temperature ranges. Simultaneously, experimental solubility of NPZH had a general order of “DMF > EGME > EG > MeOH > EGEE > EGPE > EtOH > EGBE > n-PrOH > i-PrOH”. Hirshfeld surface was employed to analyze and quantize the intermolecular interaction of NPZN during the crystal construction process. The impact of solute–solvent interaction on NPZN solubility was investigated by calculating the solvation free energies of solute in selected solvents through molecular dynamic (MD) simulation. It turned out that NPZN solubility was positively associated with solute–solvent interaction. Solubility values of NPZN were correlated by Wilson, NRTL, NRTL-SAC as well as UNIQUAC model, corresponding fitting accuracies of different model were in variation based on various root mean squared deviation (RMSD) and average relative deviation (ARD). The computational results indicated that UNIQUAC model performed the highest accuracy in correlation of experimental solubility. Finally, thermodynamic properties of dissolution process and mixing process were investigated by UNIQUAC model in this research work. The existences of negative Gibbs energy changes and positive entropy changes were observed, which suggested that the dissolution process and mixing process were always spontaneous and entropy-increasing.

The current research was devoted to the solubility profile and its computational methodologies, partial Hansen solubility parameter, inter- and intra-molecular interactions, and solvation performance for the systems formed by crystalline flutamide dissolved in water and cosolvent, i.e. ethanol/isopropanol/acetonitrile/1,4-dioxane. All solubility experimentations were done via a common shake-flask saturation method at a pressure of atmosphere (p = 101.2 kPa) and the temperature range from 278.15 to 323.15 K. The solubility in magnitudes of flutamide were recorded as the lowest in pure water at 278.15 K; and the highest in pure co-solvent at 323.15 K. The three-dimensional Hansen solubility parameters were utilized here to illustrate the solubility profile. The quantifiable explanation of solvent effect was carried out via modelling the flutamide solubility using linear solvation energy relationships. Satisfactory outcomes for correlating the solubility magnitudes were realized by means of modified van’t Hoff–Jouyban–Acree, modified Wilson and Jouyban–Acree models with the relative average errors of

The mole fraction solubility of 2-methyl-4-nitroaniline in binary mixed solvents of (ethyl acetate + methanol), (ethyl acetate + ethanol), (ethyl acetate + n -propanol) and (ethyl acetate + isopropanol) was determined experimentally by using static method at temperatures from (278.15 to 313.15) K under atmospheric pressure. The solubility increased with increasing temperature and mass fraction of ethyl acetate. At the same temperature and mass fraction of ethyl acetate, the mole fraction solubility in (ethyl acetate + methanol) was greater than those in the other mixed solvents. The solubility values were correlated with Jouyban–Acree model, van’t Hoff-Jouyban-Acree model, modified Apelblat-Jouyban-Acree model, Ma model, and Sun model. The maximum values of relative average deviations and root-mean-square deviations were 0.47 × 10 −2 and 2.26 × 10 −4 , respectively. Preferential solvation parameters of the solute were also derived by means of the inverse Kirkwood-Buff integrals (IKBI) method. The preferential solvation parameters δx 1,3 are negative in alcohol-rich composition, but positive in intermediate and ethyl acetate-rich composition. The ethyl acetate action may be related to the breaking of the ordered structure of alcohol around the polar moieties of 2-methyl-4-nitroaniline. The positive δx 1,3 values could be explained based on the higher acidic behaviour of 2-methyl-4-nitroaniline molecules interacting with the hydrogen acceptor groups present in ethyl acetate. This work expands the physicochemical information about solid in binary solvent mixtures.

In this work, the solid-liquid phase equilibrium for binary system of succinic acid + diethylene glycol at the temperatures ranging from (298.15 to 333.15) K and ternary system of (succinic acid + urea + diethylene glycol) at 298.15 K, 313.15 K and 333.15 K was built by using the isothermal saturation method under atmospheric pressure (101.2 kPa), and the solubilities were determined by a high-performance liquid chromatography. The solid-phases formed in the ternary system of ((succinic acid + urea + diethylene glycol)) were confirmed by Schreinemaker’s method of wet residue, which corresponded to urea, succinic acid, and adduct 2:1 urea-succinic acid (mole ratio). Three isothermal phase diagrams for the ternary system were constructed based on the measured mutual solubility. Each isothermal phase diagram included six crystallization fields, three invariant curves, two invariant points and two co-saturated points. The crystalline region of adduct 2:1 urea-succinic acid is larger than those of the other two solids. The solubility of succinic acid in diethylene glycol was correlated with the modified Apelblat equation, λh equation and NRTL model; and the mutual solubility of the ternary ((succinic acid + urea + diethylene glycol)) system was correlated and calculated by the NRTL model. The interaction parameters’ values of succinic acid-urea were acquired. The value of RMSD was 7.11 × 10−3 for the ternary system. The calculation results had good agreement with the experiment values. Furthermore, the densities of equilibrium liquid phase were acquired. The phase diagrams and the thermodynamic model of the ternary system could provide the basis for design of the adductive crystallization process which was used to separate succinic acid with high purity from dicarboxylic acid mixtures.