The effect of sintering temperature on the properties of the BiOCl films for potential application in DSSC

In this work, BiOCl films were obtained by tape casting using BiOCl powders synthesized by the co-precipitation method. The effect of the film's sintering temperature (300 °C–600 °C) on the morphology, chemical composition, crystalline phases and optical characteristics was studied. The obtained BiOCl powders showed a flake-like morphology, a tetragonal crystalline structure without secondary phases and a wide band gap of 3.53 eV. For BiOCl films, results indicated that as the sintering temperature increased the flake-like shaped particles changed to rectangular ones while the amount of chlorine in the films decreased. A phase transition from tetragonal BiOCl to monoclinic Bi24O31Cl10 was also observed as the sintering temperature increased. Consequently, optical studies revealed that the band gap of BiOCl films decreased from 3.03 eV to 2.82 eV. FTIR analysis demonstrated that the organic groups were removed from the films only for sintering temperatures above 400 °C. The Rhodamine B dye adsorption capacity of BiOCl films decreased with increasing sintering temperature. The results obtained allow us to conclude that BiOCl films are suitable for use in DSSC when the sintering temperature is in the range of 400–500 °C

Singular Location and Signaling Profile of Adenosine A2A-Cannabinoid CB1 Receptor Heteromers in the Dorsal Striatum

The dorsal striatum is a key node for many neurobiological processes such as motor activity, cognitive functions, and affective processes. The proper functioning of striatal neurons relies critically on metabotropic receptors. Specifically, the main adenosine and endocannabinoid receptors present in the striatum, ie, adenosine A2A receptor (A2AR) and cannabinoid CB1 receptor (CB1R), are of pivotal importance in the control of neuronal excitability. Facilitatory and inhibitory functional interactions between striatal A2AR and CB1R have been reported, and evidence supports that this cross-talk may rely, at least in part, on the formation of A2AR-CB1R heteromeric complexes. However, the specific location and properties of these heteromers have remained largely unknown. Here, by using techniques that allowed a precise visualization of the heteromers in situ in combination with sophisticated genetically-modified animal models, together with biochemical and pharmacological approaches, we provide a high resolution expression map and a detailed functional characterization of A2AR-CB1R heteromers in the dorsal striatum. Specifically, our data unveil that the A2AR-CB1R heteromer (i) is essentially absent from corticostriatal projections and striatonigral neurons, and, instead, is largely present in striatopallidal neurons, (ii) displays a striking G protein-coupled signaling profile, where co-stimulation of both receptors leads to strongly reduced downstream signaling, and (iii) undergoes an unprecedented dysfunction in Huntington’s disease, an archetypal disease that affects striatal neurons. Altogether, our findings may open a new conceptual framework to understand the role of coordinated adenosine-endocannabinoid signaling in the indirect striatal pathway, which may be relevant in motor function and neurodegenerative diseases

Cardiac electrical defects in progeroid mice and Hutchinson-Gilford progeria syndrome patients with nuclear lamina alterations

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disease caused by defective prelamin A processing, leading to nuclear lamina alterations, severe cardiovascular pathology, and premature death. Prelamin A alterations also occur in physiological aging. It remains unknown how defective prelamin A processing affects the cardiac rhythm. We show age-dependent cardiac repolarization abnormalities in HGPS patients that are also present in the Zmpste24−/− mouse model of HGPS. Challenge of Zmpste24−/− mice with the β-adrenergic agonist isoproterenol did not trigger ventricular arrhythmia but caused bradycardia-related premature ventricular complexes and slow-rate polymorphic ventricular rhythms during recovery. Patch-clamping in Zmpste24−/− cardiomyocytes revealed prolonged calcium-transient duration and reduced sarcoplasmic reticulum calcium loading and release, consistent with the absence of isoproterenol-induced ventricular arrhythmia. Zmpste24−/− progeroid mice also developed severe fibrosis-unrelated bradycardia and PQ interval and QRS complex prolongation. These conduction defects were accompanied by overt mislocalization of the gap junction protein connexin43 (Cx43). Remarkably, Cx43 mislocalization was also evident in autopsied left ventricle tissue from HGPS patients, suggesting intercellular connectivity alterations at late stages of the disease. The similarities between HGPS patients and progeroid mice reported here strongly suggest that defective cardiac repolarization and cardiomyocyte connectivity are important abnormalities in the HGPS pathogenesis that increase the risk of arrhythmia and premature death

Photochemical deposition, characterization and optical properties of thin films of ThO2

Thorium oxide thin films were successfully prepared by direct UV irradiation of amorphous films composed of thorium(IV) β-diketonate precursor complexes on Si(100) and quartz substrates. The ThO2 films were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and atomic force microscopy (AFM). The X-ray diffraction patterns showed that the films that annealed at T° below 550 °C were amorphous. The films that annealed at 550 °C and above exhibited a preferred orientation along the (111) plane. Both the as-photodeposited and annealed ThO2 films exhibited a good optical quality with transparency in the visible region better than 85%. Photoluminescence of ThO2 thin films was reversibly quenched when exposed to 60 ppm of CO at room temperature

Effect of supporting electrolyte concentration on one-step electrodeposited CuInS2 films for ZnS/CuInS2 solar cell applications

A one-step electrodeposition process was used to obtain CuInS2 (CIS) films on a molybdenum substrate by varying the supporting electrolyte (lithium chloride, LiCl) concentration. The as-deposited samples were characterized by scanning electron microscopy, energy-dispersive spectroscopy, profilometry, and diffuse reflectance spectroscopy. From characterization, it was found that different concentrations of LiCl mainly lead to a morphological change in the obtained CIS films. Moreover, their chemical composition shifted to the stoichiometric composition for high concentrations of the supporting electrolyte. After annealing, the structural analysis from X-ray diffraction revealed that all samples crystallized in the tetragonal phase of CIS. In addition, it was found that the crystallite size increased for samples grown at higher concentrations of LiCl. Optical studies carried out by diffuse reflectance spectroscopy revealed that the band gap values increased from ~ 1.40 to ~ 1.45 eV (average) after the annealing process. Finally, zinc sulfide (ZnS) thin films were chemically deposited onto electrodeposited CIS films in order to evaluate the photovoltaic response of ZnS/CIS bilayer systems. We discovered that ZnS thin films covered the surface of CIS more effectively for the highest concentration of LiCl and that only the ZnS/CIS bilayer with the CIS film obtained at the highest concentration of LiCl showed a photovoltaic response.This work was financially supported by the Comisión Nacional de Ciencia y Tecnología (CONICYT) through the project FONDECYT Iniciación 11160368 and Gobierno de Aragón–Fondo Social Europeo (E14 17R).Peer reviewe

Range extension: records of Anarhichas denticulatus (Perciformes: Anarhichadidae) caught in the southern Bay of Biscay (NE Atlantic)

Signalements les plus méridionaux de Anarhichas denticulatus (Perciformes : Anarhichadidae) capturés dans le sud du golfe de Gascogne (NE Atlantique). Deux spécimens adultes d’Anarhichas denticulatus (Krøyer, 1845) ont été capturés pour la première fois dans la partie méridionale du golfe de Gascogne (Nord-Est Atlantique). Ces nouvelles occurrences permettent d’élargir considérablement vers le sud, l’aire de répartition de cette espèce et de fournir de plus amples informations sur certains aspects de sa biologie.Versión del editor0,404

Study of the influence of Er/Ln co-doping in La2O3 thin films on their up-conversion properties (where Ln ¼ Ho or Nd)

In this study we report significant enhancement of up-conversion emissions of La2O3:Er thin films when they are co-doped with Er/Ln (where Ln = Nd or Ho). The proposed mechanisms by which the Ln ions contribute to these emissions are based on different mechanistic routes. While the La2O3 samples co-doped with Er/Nd involves energy transfer Nd-III -> E-III processes, in the La2O3 samples co-doped with Er/Ho involves energy transfer Er-III -> Ho-III processes. All samples were synthesized by a solid state photochemical deposition method followed by a subsequent calcination process. The luminescent properties reveal that samples under 980 nm irradiation exhibit characteristic up-conversion emissions that are focused in the green region of the spectrum and that the nature of second activator (Ln) determines the degree of efficiency of these emissions.CONICYT-FONDEQUIP-Chile Program EQM-140088 Research Office at the University of Bio-Bio, project DIUBB 181109-4/R CONICY-FONDECYT Program (National Fund for Scientific and Technological Development), Chile 119035

Study of the early growth stages of chemically deposited ZnS thin films from a non-toxic solution

ZnS thin films grown by the chemical bath deposition method have been under intense investigation due to their applications in solar cells. In this work, the early growth stages of ZnS thin films deposited by means of a non-toxic solution are studied by measuring the morphological, chemical and optical properties of the films obtained at different deposition time (5, 10, 20, 30, 60, 90 and 120 min). From the atomic force microscopy (AFM)studies, it was seen that the substrate surface is not fully covered before 20 min, and the growth exponential value changed from 0.5 to 1.8. The x-ray photoelectron spectroscopy (XPS) measurements revealed the presence of the Zn–O bond and the absence of the S– Zn bond at the earliest deposition time. Additionally, from XPS analysis, a shift in the signals for O1s and Zn2p3/2 for the sample grown at 30 min was observed due to the formation of Zn(OH)2. Finally, the UV-Vis spectrophotometry measurements showed that all samples have a high transmittance (>80%) and that the band gap value decreased as the deposition time increased

Modification of the junction parameters via Al doping in Ag/CdS:Al thin-film Schottky diodes for microwave sensors

In this article, it is investigated the effect of Al doping in the junction parameters of Ag/CdS:Al thin-film Schottky diodes and their electrical response to microwave irradiation. Nanocrystalline CdS:Al thin-films with thicknesses between 109 and 173 nm were prepared by chemical bath deposition and, subsequently, Ag thin-films with an average thickness of 102 nm were grown on the CdS:Al using dc sputtering. The structural, chemical, morphological and optical properties of CdS:Al and Ag films were characterized by x-ray diffraction (XRD), scanning electron microscope, atomic force microscope, energy-dispersive x-ray spectroscopy and UV-Vis spectrophotometer, respectively. Current-voltage ( I − V ) characteristics of Ag/CdS:Al diodes, with different Al content, were obtained at room temperature in dark conditions. XRD studies shows that CdS:Al and Ag thin-films have an hexagonal and cubic structure, respectively. Crystallite sizes decreases with Al content for CdS:Al films and were found to be in the 15–40 nm range. A decrease in the intensity of the XRD main peak of CdS:Al films is observed, caused by the inclusion of amorphous Al _2 O _3 on the CdS film. It was found that band gap of CdS:Al films increases with increasing Al content, from 2.28 eV to 2.40 eV. Based on the I − V characteristics of the diodes, their barrier height ϕ _0 , ideality factor n , and series resistance R _s were calculated, and it was found that these values are modified by increasing Al content in CdS films, in the ranges: ϕ _0 : 0.7037–0.8426 eV; n : 3.485–4.213; R _s : 0.54–9.86 MΩ. Besides, it was stated that Al doping changes the average surface roughness and the energies of the charge neutrality levels of CdS:Al films. The effects of physical properties of the films on the junction parameters of the diodes were also discussed. Finally, I − V characteristics of the Ag/CdS:Al diodes were studied under X-band microwave irradiation at room temperature in dark conditions. For a specific Al doping value, the current density across the diode during irradiation was found to be lower (0.87–11.6 mA cm ^−2 ) than unirradiated diode (1.14–15.6 mA cm ^−2 ), when the bias voltage was higher than certain value (3 V), due to an increasing temperature of the diode and the presence of Al _2 O _3 on the CdS:Al film. This last result could be useful in a potential X-band thin-film microwave sensor