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In this work, we use ultra-thin thickness-controllable spatial atomic layer deposited (ALD) aluminium oxide (AlOx) tunnel layers, which contain high negative fixed charges (Qf), capped by highly boron-doped polysilicon layers to form tunnel layer passivated contacts. The high Qf of the tunnel layers is expected to enhance the carrier selectivity of these passivated hole-extracting contacts. The dependence of the ALD AlOx tunnel layer contact passivation performance on its thickness is investigated. Furthermore, two different thermal charge activation conditions, i.e., fast firing using a belt furnace at 700 and 800 °C are compared. The best measured recombination current density J0 and implied open-circuit voltage iVoc of the developed AlOx/polysilicon passivated contacts with a symmetrical AlOx/SiNx stack passivation are 6.6 fA/cm2 and 723 mV, respectively. Based on the measured J0 and on the measured total contact resistivity of the passivated contact, the practical efficiency limit of a rear-side full area passivated contact solar cell with a conventionally diffused front side is calculated to be as high as 23.2%. Additionally, three rear-side metallization schemes: (1) thermally evaporated full-area silver contacts; (2) screen-printed non-firing-through aluminium contacts and (3) screen-printed firing-through silver-aluminium contacts, are compared. Finally, rear-emitter solar cells, using a rear-side hole-selective AlOx tunnel layer passivated contact, are fabricated, which shows an efficiency of up to 20.5%. While the proposed hole-selective passivated contact scheme appears to be promising based on the simulation prediction, the efficiency of the fabricated cells is largely limited by the non-optimized front-side reflectance and recombination losses as well as the use of non-optimized rear-side metallization schemes.

In this work, we demonstrate the feasibility and attractiveness of combining an ultra-thin atomic layer deposited aluminium oxide (ALD-AlOx) tunnel oxide layer with a commercially available low cost doped organic capping layer with high workfunction, PEDOT:PSS, to form an excellent hole-selective passivated contact for solar cell applications. We present a systematic methodology of measuring the most important parameters, i.e. determining the passivation quality (the saturation current density) and the contact resistance for our investigated hole-selective passivated contacts, and incorporating those into our developed solar cell efficiency potential prediction model to assess their performance at the final device level. In particular, we had studied in detail the impact of the choice of a suitable tunnel layer (ALD-AlOx, as compared to a “standard” wet-chemically formed wet-SiOx tunnel layer), the impact of tunnel layer thickness and tunnel layer anneal conditions (no-anneal, ambient anneal, forming gas anneal, fast-firing), as well as the influence of different capping layers (PEDOT:PSS, as compared to a “standard” p+-poly-Si capping layer) on the extracted parameters. Due to its high negative interface charges, it is advantageous to use an ultra-thin ALD-AlOx tunnel oxide instead of a commonly reported wet-SiOx tunnel oxide for hole carrier extraction. Combining that with either a highly p-doped poly-silicon capping layer or a commercially available low cost, high workfunction, doped organic capping layer like PEDOT:PSS, it is possible to achieve a practical cell efficiency potential exceeding 21%, if integrating the tunnel layer passivated hole contact at the rear-side of an otherwise conventionally processed solar cell.

The molecular dynamics (MD) simulation method was used to investigate the hydrogen bonding energy of starch/glycerol system under different temperatures (range from 90 °C to 120 °C) and different glycerol contents (range from 20% to 40%, based on dry starch weight). These effects on the hydrogen bonding energy (including the total hydrogen bonding energy, hydrogen bonding energy of starch/starch, glycerol/glycerol, and starch/glycerol) were analyzed in detail. Meanwhile, glycerol plasticized starch films were prepared using casting method. The relationship between the hydrogen bonding energy and the performances of thermoplastic starch film (TPSF), such as crystallinity, mechanical properties and water uptake determined experimentally, were revealed and discussed. The results indicated that glycerol/starch film contained strong hydrogen bonding interaction which could be increased by decreasing the temperature or increasing the glycerol content. The hydrogen bonding interaction is the key factor for the preparation of the plasticized starch material, and the plasticized mechanism can be interpreted according to the analytical results of the simulation.

This work explores the possibility of using ultrathin silicon nitride (SiN x ) films with high positive fixed charge in a SiN x /poly-Si passivating contact. The factors including (i) film thickness, (ii) annealing condition (time, temp and ambient) and (iii) surface pre-treatment were optimized to boost the passivation performance of ultrathin LPCVD SiN x films. Our preliminary experiments reveal excellent surface passivation and low recombination current density, J o (45 fA.cm-2) by ~1.5 nm thick LPCVD SiN x films when subjected to an air ambient anneal at 800°C for 30 mins. This is due to the formation of high positive fixed charge density (1.5 ×10 12 cm-2). Air ambient annealed (465 μs) samples also have a higher lifetime when compared to the forming gas annealed (208 μs) samples. These passivating SiN x films were further integrated into SiN x /n+poly-Si contacts and characterized for J o,contact and tunneling resistance, ρ contact . The best SiN x /n+poly-Si passivated contact in this study has J o, contact = 5.9 fA.cm-2, ρ contact = 0.525 Ω.cm2 and an efficiency potential > 22.75%. According to our knowledge, it is the first report confirming the formation of passivated contacts with SiN x as the dielectric tunnel layer.

The evolution mechanism and energy conversion of volatile in low-rank coal with pyrolysis temperatures still remain uncertain. The experimental results on gas products and light tar pyrolyzed from Shenfu coal at various pyrolysis temperatures reflect the complex correlation between volatiles and coal structure affected by temperatures. Thermodynamic competitive evolution towards CO from oxygen-containing structures are analyzed by density functional theory. The formation mechanisms of polycyclic aromatic hydrocarbons (PAHs) from by-product cyclopentadienyl through Diels-Alder reaction and C–H β-scission are confirmed at the CBS-QB3//M06–2X/def2-TZVP level of theory. Kinetic rate coefficients of the rate-limiting step are computed. Thermodynamic and kinetic calculation results indicate that phenols pyrolysis have to cross a higher energy barrier. Moreover, cyclopentadienyl thermodynamically tends to form indene at 645 °C, while forming PAHs such as naphthalene, even fluorene, phenanthrene, and anthracene at 855 °C, which is consistent with the experimental results. A hydrogen-rich environment can kinetically facilitate the formation of PAHs.

Carbon nanotubes (CNTs) can be formed during catalytic reforming of hydrocarbons with H2 co-production over Ni-based catalysts. Normally, the formed CNTs need to be separated from original catalysts in order to be coated on the substrates to make high performance electrodes. To simplify the traditional preparation process, a novel one-step method for simultaneously producing a CNTs electrode material and H2 was proposed. A Ni-Fe modified Ni foam (Ni-Fe/NF) was chosen as both catalyst and electrode substrate to in situ grow nitrogen-doped carbon nanotubes (N-CNTs) during catalytic reforming of pyrrole. Pyrrole was selected as an N-containing model compound of biomass tar. The results showed that Ni-Fe nanoparticles on Ni-Fe/NF catalyst remarkably improved the H2 production and pyrrole conversion, which increased by more than 20 times than those of fresh Ni foam. Besides, a significant amount of multi-walled CNTs with more than 40 graphite layers grew on the surface of spent catalyst and their diameters were mainly from 10 nm to 20 nm. N element was detected on the formed CNTs and the Graphitic-N was the main type of N-doping. The spent catalyst (N-CNTs@Ni foam) can be directly used as a composite electrode material with high performance and stability. Its electrochemical capacitance reached 855 mF/cm2 at a current density of 5 mA/cm2 and remained over 95% after 10,000 cycles.

Angelica sinensis (AS) is an important medicinal plant, and volatile oil is the main pharmacologically active ingredient. This study was aimed to investigate the anti-inflammatory activity of the volatile oil of A. sinensis (VOAS) and explore its potential anti-inflammatory mechanism by plasma metabolomics approach. Rat acute inflammation was induced by subcutaneous injection of carrageenan in hind paws. Paw edema, histamine (HIS) and 5-hydroxytryptamine (5-HT) were detected. Then, we analyzed plasma metabolic profiling of acute inflammation and performed pathway analysis on the metabolite markers reversed after VOAS administration and further integration of metabolic networks. The results showed that VOAS could alleviate the paw edema and decrease plasma HIS and 5-HT levels. Fourteen metabolite markers of acute inflammation were screened, and the levels were all reversed to different degrees after VOAS administration. These metabolite markers mainly related to linoleic acid metabolism, ascorbate and aldarate metabolism, arachidonic acid metabolism, glyoxylate and dicarboxylate metabolism, and glycine, serine and threonine metabolism. In metabolic networks, glycine and arachidonic acid were node molecules. It indicated that VOAS could significantly inhibit systemic inflammatory response triggered by acute local stimulation and it exerted anti-inflammatory activity mainly through regulating the disturbed metabolic networks centered on glycine and arachidonic acid.

Taohong Siwu Decoction (TSD) is a classic prescription in traditional Chinese medicine and is widely used to promote blood circulation to remove blood stasis. However, the effect mechanisms are not yet well understood. Here, a urinary metabolomic approach based on liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC/Q-TOF-MS) was conducted to explore the changes in the endogenous metabolites and to assess the integral efficacy of TSD on acute blood stasis model rats. Then, parameters for hemorheology and coagulation functions were detected. Principal component analysis (PCA) and orthogonal partial least squares discriminate analysis (OPLS-DA) was used to investigate the global metabolite alterations and to evaluate the preventive effects of TSD in rats. Potential metabolite markers were found using OPLS-DA and t-test. Furthermore, metabolic pathway analysis was performed to construct metabolic networks. The results showed that TSD could significantly decrease whole blood viscosity and plasma viscosity. It also significantly prolonged partial thromboplastin time (APPT) and prothrombin time (PT), increased thrombin time (TT) and lowered fibrinogen content (FIB). Moreover, 24 potential metabolite markers of acute blood stasis were screened, and the levels were all reversed to different degrees after TSD administration. In metabolic networks, amino acid metabolism (arginine and proline metabolism; histidine metabolism; alanine, aspartate, and glutamate metabolism; phenylalanine, tyrosine, and tryptophan biosynthesis; phenylalanine metabolism) and lipid metabolism (glycerophospholipid metabolism; linoleic acid metabolism; alpha-linolenic acid metabolism) were closely related with the intervention mechanism of TSD on acute blood stasis. The urinary metabolomic approach can be applied to clarify the mechanism of TSD in promoting blood circulation to remove acute blood stasis and to provide the theoretical basis for further research on the therapeutic mechanism of TSD in clinical practice.

Metabonomics based on GC-MS was used to study the possible anti-inflammatory mechanisms of volatile oils of Angelica sinensis (VOAS) in rats with acute inflammation. Acute inflammation was induced by subcutaneous injection of carrageenan in rats. The levels of prostaglandin E2 (PGE2 ), histamine (HIS) and 5-hydroxytryptamine (5-HT) in the inflammatory fluid were detected. Principal component analysis and orthogonal partial least squares-discriminant analysis models were performed for pattern recognition analysis. After the administration of VOAS, the levels of PGE2 , HIS, and 5-HT returned to levels observed in normal group. According to GC-MS analysis, the intervention of VOAS in rats with acute inflammation induced substantial and characteristic changes in their metabolic profiles. Fourteen metabolite biomarkers, namely, lactic acid, malic acid, citric acid, trans-dehydroandrosterone, aldosterone, linoleic acid, hexadecanoic acid, pregnenolone, octadecenoic acid, myristic acid, l-histidine, octadecanoic acid, arachidonic acid (AA) and l-tryptophan, were detected in the inflammatory fluid. The levels of all biomarkers either increased or decreased significantly in model groups. VOAS possibly intervened in the metabolic process of inflammation by altering histidine metabolism, tryptophan metabolism, AA metabolism, steroid hormone biosynthesis, fatty acid metabolism and energy metabolism. Metabonomics was used to reflect an organism's physiological and metabolic state comprehensively, and it is a potentially powerful tool that reveals the anti-acute-inflammatory mechanism of VOAS.

Angelica sinensis polysaccharides (ASP) have an established hepatoprotective effect, but the mechanism for this effect remains unclear. A novel approach using biochemical parameters coupled with metabolomics based on gas chromatography-mass spectrometry (GC-MS) and chemometrics was established in this study to explain the hepatoprotective effect mechanism of ASP. The superoxide dismutase activity, malonaldehyde content, alanine aminotransferase, aspartate aminotransferase, and γ-glutamyl transpeptidase in plasma were measured. Pathological changes in the liver were observed. Plasma and liver homogenate obtained from mice were analyzed using GC-MS. Distinct changes in metabolite patterns in the plasma and liver homogenate after being induced by carbon tetrachloride and drug intervention were observed using principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA). Potential biomarkers were found using PLS-DA and T-test. The results of the pathological changes observed in the liver, the biochemical parameters in plasma, and the metabolomics of the plasma and liver homogenate all showed that liver injury was successfully reproduced, ASP exhibited hepatoprotective effect, and the medium dose of ASP exhibited the best. Nine endogenous metabolites in the liver homogenate and ten endogenous metabolites in the plasma were all considered as potential biomarkers. They were considered to be in response to hepatoprotective effects of ASP involved in the amino acids metabolism, energy metabolism, and lipids metabolism. Therefore metabolomics is a valuable tool in measuring the efficacy and mechanisms of action of traditional Chinese medicines.

In this work, hydrogen plasma etching of surface oxides was successfully accomplished on thin (∼100 µm) planar n-type Czochralski silicon wafers prior to intrinsic hydrogenated amorphous silicon [a-Si:H(i)] deposition for heterojunction solar cells, using an industrial inductively coupled plasma-enhanced chemical vapour deposition (ICPECVD) platform. The plasma etching process is intended as a dry alternative to the conventional wet-chemical hydrofluoric acid (HF) dip for solar cell processing. After symmetrical deposition of an a-Si:H(i) passivation layer, high effective carrier lifetimes of up to 3.7 ms are obtained, which are equivalent to effective surface recombination velocities of 1.3 cm s–1 and an implied open-circuit voltage (Voc) of 741 mV. The passivation quality is excellent and comparable to other high quality a-Si:H(i) passivation. High-resolution transmission electron microscopy shows evidence of plasma-silicon interactions and a sub-nanometre interfacial layer. Using electron energy-loss spectroscopy, this layer is further investigated and confirmed to be hydrogenated suboxide layers. (© 2015 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)

In this paper, an operative water-in-oil micro-emulsion method for the preparation of well-dispersed templates and the preparation of hollow spheres from the templates were presented. The hollow spheres were obtained via the cross-linking of acidic SiO2 sol on the surface of cross-linked polyvinyl alcohol (CPVA) templates under base condition and the following calcinations process at 800 °C. The XRD results indicated that the hollow silica spheres were composed of amorphous phase. Well-dispersed templates and silica hollow spheres were characterized by scanning electron microscope (SEM) and field emission scanning electron microscope (FESEM) respectively. The results showed that the as-synthesized hollow silica microspheres were hollow spheres with diameter of 1–20 μm, wall thickness of 0.2–3 μm. The thickness of the hollow microspheres could be controlled by the parameter of the reaction condition. Moreover, some “bowl shaped” new structures were detected in the samples with the low ratio of silica sol and CPVA microspheres.

Heterojunction silicon wafer solar cells, using a microcrystalline silicon (μc-Si:H) thin-film emitter and a very thin intrinsic amorphous silicon (a-Si:H) passivation layer between the crystalline silicon wafer and the emitter layer, have been reported to exhibit stable performance and high efficiency. Desired properties for the emitter layer include wide bandgap, low surface and interface recombination, and good doping efficiency. In this study, we report on the thin-film properties of p-doped μc-Si:H emitter layers deposited using RF (13.56 MHz) PECVD, at different SiH4/H2 gas flow ratios, pressures, and temperatures at the same RF power. Trends relating deposition conditions to relevant film characteristics such as thickness, crystalline fraction and conductivity are discussed. Finally, device relevant symmetrical p+/i/c-Si/i/p+ heterojunction lifetime test structures are investigated, using the optimised parameters for p-doped μc-Si:H layers (discussed in this paper) and for intrinsic a-Si:H layers (discussed in a companion paper [1] ). These exhibit promising effective lifetimes of up to 2.4 ms at an injection level of 1015 cm-3.

We demonstrate a new contact technology for realizing a near band edge contact Schottky barrier height (FB) in black phosphorus (BP) p- channel transistors. This is achieved via the use of high work function nickel (Ni) and thermal anneal to produce a novel nickelphosphide (Ni2P) alloy which enables a record low hole FB of 12 meV. The formation of reactive Ni2P/ BP contact was found to further improve the transmission probability as compared to the Ni/ BP contact. Moreover, the penetration of Ni2P in the source and drain regions could additionally reduce the parasitic series resistance, leading to drive current improvement.

To evaluate the anti-acute inflammation effects of volatile oils from different processed products of Angelicae Sinensis Radix(AS) in the rat model of acute inflammation established by the metabolomic method. Volatile oil of charred AS (C-VOAS), wine-processed AS (J-VOAS), locally processed AS (T-VOAS) and oil-process AS (Y-VOAS) were applied to intervene the rat acute paw swelling inflammation model induced by Carrageenan. Changes in serum HIS, 5-HT, PGE2 and TNF-α content in rats were detected. Gas chromatography-mass spectrometry was used to detect the metabolites in plasma. Potential biomarkers were investigated according to principal component analysis method and partial least-squares discriminant analysis. According to the results, C-VOAS and J-VOAS could significantly inhibit inflammatory mediators Histamine, 5-hydroxytryptamine, prostaglandin-E2 and cytokine tumor necrosis factor-alpha (P

This study aimed at determining the effects of Angelica sinensis (AS) on urinary metabolites in blood deficiency mice and exploring its replenishing blood mechanism. Gas chromatography-mass spectrometry (GC-MS) was applied to detect metabolites in the urine samples in different collection periods. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to investigate the differences in metabolic profiles among control group (CG), blood deficiency model group (MG), AS groups, and Colla Corii Asini group (CCAG). The potential biomarkers were identified based on the variable importance in the projection (VIP), T-test, and National Institute of Standards and Technology (NIST) and mass spectra library. The metabolites were analyzed using metabolomics pathway analysis (MetPA) to build the metabolic pathways. Our results indicated that, on the seventh day, the levels of glucose, lactic acid, pyruvic acid, alanine, acetoacetic acid, and citric acid changed significantly in blood deficiency mice. However, these metabolic deviations came to closer to normal levels after AS intervention. The reversing blood-deficiency mechanism of AS might involve regulating synthesis and degradation of ketone bodies, Pyruvate metabolism, TCA cycle, and Glycolysis/Gluconeogenesis. In conclusion, metabonomics is a robust and promising means for the identification of biomarkers and elucidation of the mechanisms of a disease, thereby highlighting its importance in drug discovery.

A novel approach using metabolomics coupled with a metabolic network was used to investigate the effects of Tao-Hong-Si-Wu decoction (THSWD) on the rat model of acute blood stasis syndrome. Acute blood stasis syndrome was induced by placing the rats in ice-cold water following two injections with epinephrine. The hemorheological indicators [whole blood viscosity (WBV) and plasma viscosity (PV)] and the blood coagulation indicators [thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (FIB)] were detected. The nonparametric univariate method and multivariate statistical analysis were performed for determining the potential biomarkers. A correlation map was structured between biochemical indicators and hub metabolites to explain the effects mechanism of THSWD. After the administration of THSWD, the levels of WBV, PV, TT, APTT and FIB returned to levels observed in the control group. According to metabolomics coupled with metabolic network analysis, the intervention of THSWD in rats with acute blood stasis syndrome induced substantial and characteristic changes in their metabolic profiles. Fifteen metabolites were screened, which mainly involved 10 pathways and five hub metabolites, namely, l-glutamate, l-phenylalanine, N-acylsphingosine, arachidonic acid and phosphatidate. The biochemical indicators and hub metabolites could be adjusted to close to normal levels by THSWD. Therefore, combining metabolomics and metabolic network helped to evaluate the effects of THSWD on acute blood stasis.

The surface passivation performance of atomic layer deposited ultra-thin aluminium oxide layers with different thickness in the tunnel layer regime, i.e., ranging from one atomic cycle (~0.13 nm) to 11 atomic cycles (~1.5 nm) on n-type silicon wafers is studied. The effect of thickness and thermal activation on passivation performance is investigated with corona-voltage metrology to measure the interface defect density D it(E) and the total interface charge Q tot. Furthermore, the bonding configuration variation of the AlO x films under various post-deposition thermal activation conditions is analyzed by Fourier transform infrared spectroscopy. Additionally, poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) is used as capping layer on ultra-thin AlO x tunneling layers to further reduce the surface recombination current density to values as low as 42 fA/cm2. This work is a useful reference for using ultra-thin ALD AlO x layers as tunnel layers in order to form hole selective passivated contacts for silicon solar cells.

Excellent c-Si tunnel layer surface passivation has been obtained recently in our lab, using atomic layer deposited aluminium oxide (ALD AlO x ) in the tunnel layer regime of 0.9 to 1.5 nm, investigated to be applied for contact passivation. Using the correspondingly measured interface properties, this paper compares the theoretical collection efficiency of a conventional metal–semiconductor (MS) contact on diffused p+ Si to a metal–semiconductor–insulator–semiconductor (MSIS) contact on diffused p+ Si or on undoped n-type c-Si. The influences of (1) the tunnel layer passivation quality at the tunnel oxide interface (Q f and D it), (2) the tunnel layer thickness and the electron and hole tunnelling mass, (3) the tunnel oxide material, and (4) the semiconductor capping layer material properties are investigated numerically by evaluation of solar cell efficiency, open-circuit voltage, and fill factor.

Passivated contacts for solar cells can be realized using a variety of differently formed ultra-thin tunnel oxide layers. Assessing their interface properties is important for optimization purposes. In this work, we demonstrate the ability to measure the interface defect density distribution D it(E) and the fixed interface charge density Q f for ultra-thin passivation layers operating within the tunnel regime (

Ethnopharmacological relevance Angelica sinensis (AS) has been used in traditional Chinese medicine for thousands of years to enrich and invigorate blood. In this study, the aim is to investigate the influence of AS on metabolism of blood deficiency mice model and to explore its anti-blood deficiency mechanism. Materials and methods The blood deficiency mice model was induced by being hypodermically injected with N-acetyl phenylhydrazine (APH) and being intraperitoneally injected with cyclophosphamide (CTX). Gas chromatography–mass spectrometry (GC–MS), principle component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were used to identify potential biomarkers in plasma and splenic tissue. Results The levels of white blood cell (WBC), red blood cell (RBC), hemoglobin (HGB) and platelet (PLT) showed a trend to return to control group after administrating with AS, while the dose of 10 g/kg showed the best effect. Potential metabolite biomarkers (nine in the plasma and nine in the spleen homogenates) were identified in this study. These biomarkers were mainly related to five metabolic pathways, such as arachidonic acid metabolism, valine, leucine and isoleucine biosynthesis, glycine, serine and threonine metabolism, arginine and proline metabolism and TCA cycle. Conclusion Metabolomics was used to reflect an organism׳s physiological and metabolic state comprehensively, indicating that metabolomics was a potentially powerful tool to reveal the anti-blood deficiency mechanism of AS.

One of the most promising advanced solar cell designs for x :H(i) have yielded very good results compatible with high-voltage HET solar cells, with the passivation quality of a-SiO x :H(i) being consistently higher, and far less sensitive to the deposition temperature compared to a-Si:H(i). In fact, a-SiO x :H(i) has a stable process window of more than 200°C that is suitable for the production environment. The wider process window can be attributed to suppressed epitaxial growth and incubation layer thickness in the a-SiO x :H(i) layer at high deposition temperatures.

Two-dimensional phosphorene is a promising channel material for next generation transistor applications due to its superior carrier transport property. Here, we report the influence of thermal effects on the Raman phonon of few-layer phosphorene formed on hafnium-dioxide (HfO2) high-k dielectric. When annealed at elevated temperatures (up to 200 °C), the phosphorene film was found to exhibit a blue shift in both the out-of-plane (A1g) and in-plane (B2g and A2g) phonon modes as a result of compressive strain effect. This is attributed to the out-diffusion of hafnium (Hf) atoms from the underlying HfO2 dielectric, which compresses the phosphorene in both the zigzag and armchair directions. With a further increase in thermal energy beyond 250 °C, strain relaxation within phosphorene eventually took place. When this happens, the phosphorene was unable to retain its intrinsic crystallinity prior to annealing, as evident from the broadening of full-width at half maximum of the Raman phonon. These results provide an important insight into the impact of thermal effects on the structural integrity of phosphorene when integrated with high-k gate dielectric.

We report on the demonstration of photodetectors based on large scale two-dimensional molybdenum disulfide (MoS2) transition metal dichalcogenides. Excellent film uniformity and precise control of the MoS2 thickness down to a monolayer (~0.75nm) were achieved by magnetron sputtering synthesis approach. In particular, the photodetectors integrated with five MoS2 monolayers exhibit a high photoresponsivity of 1.8 A/W, an external quantum efficiency exceeding 260%, and a photodetectivity of ~5 x 108 Jones for a wavelength of 850 nm, surpassing the performance of mechanically exfoliated based photodetectors.

A simple restricted-access media (RAM) HPLC method for simultaneous determination of the lactone and carboxylate forms of 10-hydroxycamptothecin (HCPT) in human serum was established. Using a RAM Hisep analytical column, serum samples were directly injected into the HPLC system. The eluted peaks of two forms of HCPT were monitored with a fluorescence detector. The separation was completed in 17 min. The linear range was 20–1000 ng/ml, intra-day and inter-day variations being less than 5%. The kinetic equation was introduced according to the analytical results. The equation shows that the course of the HCPT lactone form converting to carboxylate form in human serum at 4 °C is a first-order kinetic course. The concentration of each form at the moment of sampling was calculated by extrapolation.

The structure and quality of intrinsic hydrogenated amorphous silicon thin films are studied with intended use as passivation layer in heterojunction silicon wafer solar cells. The thin film layers are formed by radio-frequency parallel-plate plasma-enhanced chemical vapor deposition. While the passivation quality of the films is found to improve steadily with increasing deposition temperature, a very narrow process window in terms of pressure variation is observed. The best effective lifetime is obtained at a hydrogen to silane dilution ratio of 1 and a pressure of 66.7 Pa for the used tool configuration. Raman crystallinity and Urbach energy obtained from fitting ellipsometry data confirm that the degradation of the passivation quality outside the process window is due to a phase change into microcrystalline silicon with different growth mechanisms and an increase in bonding related defects. Film growth mechanisms are proposed to account for the observed narrow process window, which are verified by optical emission spectroscopy measurements.

Heterojunction silicon wafer solar cells using an intrinsic amorphous silicon (a-Si:H) thin-film passivation layer between the crystalline c-Si substrate and the thin-film emitter layer have proven to be a viable device structure for high efficiency. While microcrystalline μc-Si:H is a good candidate for the emitter layer due to its high doping efficiency, intrinsic a-Si:H with its low interfacial defect density, high optical bandgap and good passivation ability makes it the ideal buffer layer to passivate the crystalline silicon interface. In this study, we report the film properties of intrinsic a-Si:H passivation layers deposited using RF (13.56 MHz) PECVD, at different SiH4/H2 gas flow ratios, pressures and temperatures. Trends relating deposition conditions to relevant film characteristics, such as thickness, hydrogen bonding, optical bandgap, and effective carrier lifetime of the samples are discussed. Finally, symmetrical p+/i/c-Si wafer/i/p+ heterojunction lifetime test structures, using 20 nm thick p-doped μc-Si:H emitter layers and 10 nm thick intrinsic a-Si:H layers, were made using the optimised parameters for intrinsic a-Si:H layers (discussed in this paper) and for p-doped μc-Si:H layers (discussed in a companion paper [1] ). These yield an effective lifetime of 2.4 ms at an injection level of 1015 cm-3, and an implied Voc of 730 mV.

International audience; Novel nucleoside derivatives were developed using the strategy of “terminal N,N-dimethylation” to impart tertiary amines to a 1,2,4-triazole nucleoside. The obtained lead compounds displayed significantly improved anticancer activity with dual mechanisms of cell death via apoptosis and autophagy, offering a fresh perspective to searching for new anticancer candidates.

International audience; Nucleoside analogues represent an important class of drug candidates. With the aim of searching for novel bioactive nucleosides, we developed an efficient synthetic way to construct a series of aryl 1,2,3-triazole acyclic C-azanucleosides via Huisgen 1,3-dipolar cycloaddition. The aryl 1,2,3-triazole motifs within these azanucleosides showed coplanar features, suggesting they could act as surrogates for large planar aromatic systems or nucleobases. Moreover, several aryltriazole acyclic C-azanucleosides bearing long alkyl chains exhibited potent antiproliferative activity against various cancer cell lines via induction of apoptosis. Most interestingly, the lead compound significantly down-regulated the key proteins involved in the heat shock response pathway, representing the first anticancer acyclic azanucleoside with such a mode of action. These novel aryl 1,2,3-triazole cyclic C-azanucleosides therefore serve as promising paradigms for further exploring anticancer drug candidates.

International audience; Nucleoside derivatives are an important class of molecules in the search for bioactive compounds. In our continuing efforts to develop novel nucleoside analogs, we used the Sonogashira cross-coupling reaction to synthesize 1,2,4-triazole acyclonucleosides bearing various arylethynyl groups on the triazole nucleobase. By employing 3-iodotriazole nucleoside as the coupling substrate, the Sonogashira reaction proceeded efficiently even with alkynes, which are notoriously unreactive and challenging. Further crystal structural analysis unveiled the coplanar feature of the 3-arylethynyltriazole motifs, suggesting their potential as surrogates for large planar aromatic systems or nucleobases. Most importantly, several synthesized compounds displayed interesting antiproliferative activity against various cancer cells and induced apoptosis, highlighting that this family of triazole nucleosides might show promise as anticancer candidates.