Hydrogenated Nanocrystalline Silicon Thin Films Prepared by Hot-Wire Method with Varied Process Pressure

Hydrogenated nanocrystalline silicon films were prepared by hot-wire method at low substrate temperature (200∘C) without hydrogen dilution of silane (SiH4). A variety of techniques, including Raman spectroscopy, low angle X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), and UV-visible (UV-Vis) spectroscopy, were used to characterize these films for structural and optical properties. Films are grown at reasonably high deposition rates (>15 Å/s), which are very much appreciated for the fabrication of cost effective devices. Different crystalline fractions (from 2.5% to 63%) and crystallite size (3.6–6.0 nm) can be achieved by controlling the process pressure. It is observed that with increase in process pressure, the hydrogen bonding in the films shifts from Si–H to Si–H2 and (Si–H2)n complexes. The band gaps of the films are found in the range 1.83–2.11 eV, whereas the hydrogen content remains <9 at.% over the entire range of process pressure studied. The ease of depositing films with tunable band gap is useful for fabrication of tandem solar cells. A correlation between structural and optical properties has been found and discussed in detail

Global, regional, and national age-sex-specific mortality for 282 causes of death in 195 countries and territories, 1980-2017: a systematic analysis for the Global Burden of Disease Study 2017.

BACKGROUND: Global development goals increasingly rely on country-specific estimates for benchmarking a nation's progress. To meet this need, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 estimated global, regional, national, and, for selected locations, subnational cause-specific mortality beginning in the year 1980. Here we report an update to that study, making use of newly available data and improved methods. GBD 2017 provides a comprehensive assessment of cause-specific mortality for 282 causes in 195 countries and territories from 1980 to 2017. METHODS: The causes of death database is composed of vital registration (VR), verbal autopsy (VA), registry, survey, police, and surveillance data. GBD 2017 added ten VA studies, 127 country-years of VR data, 502 cancer-registry country-years, and an additional surveillance country-year. Expansions of the GBD cause of death hierarchy resulted in 18 additional causes estimated for GBD 2017. Newly available data led to subnational estimates for five additional countries-Ethiopia, Iran, New Zealand, Norway, and Russia. Deaths assigned International Classification of Diseases (ICD) codes for non-specific, implausible, or intermediate causes of death were reassigned to underlying causes by redistribution algorithms that were incorporated into uncertainty estimation. We used statistical modelling tools developed for GBD, including the Cause of Death Ensemble model (CODEm), to generate cause fractions and cause-specific death rates for each location, year, age, and sex. Instead of using UN estimates as in previous versions, GBD 2017 independently estimated population size and fertility rate for all locations. Years of life lost (YLLs) were then calculated as the sum of each death multiplied by the standard life expectancy at each age. All rates reported here are age-standardised

Film thickness effects on morphology, optical and structural properties of chemical bath deposition grown CdS thin films for solar cell applications

CdS thin films of varying thickness were deposited on the glass substrate by chemical bath deposition (CBD) using Cadmium Chloride (CdCl2) and Thiourea ((NH2)2CS) as Cd and S sources respectively with ammonia as a complexing agent. The synthesized CdS thin films have been characterized using X-ray diffractometer (XRD), Raman spectroscopy, UV-Vis-NIR spectrophotometer, Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Energy dispersion X-ray analysis (EDAX). From XRD analysis it is inferred that the obtained CdS films have highly orientated hexagonal structure with the preferential orientation along (002) plane. The optical characterization raveled that the films are highly transparent (60%–80%) in the visible region. From TEM analysis it has been observed that the inter planner spacing for CdS thin film is ∼0.31 nm and average crystallite size is 7–8 nm. The EDAX data revealed nearly stoichiometric characteristics of the CdS thin films. The SEM analysis showed that CdS thin films are smooth, homogeneous and uniform without cracks with randomly oriented spherical nanocrystallites. The CdS thin films have very high transmission in the range 600–1200 nm with the band gap >2.54 eV. The purpose of the present study is to develop window/buffer layer for CZTS solar cells

Film thickness effects on morphology, optical and structural properties of chemical bath deposition grown CdS thin films for solar cell applications

CdS thin films of varying thickness were deposited on the glass substrate by chemical bath deposition (CBD) using Cadmium Chloride (CdCl2) and Thiourea ((NH2)2CS) as Cd and S sources respectively with ammonia as a complexing agent. The synthesized CdS thin films have been characterized using X-ray diffractometer (XRD), Raman spectroscopy, UV-Vis-NIR spectrophotometer, Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Energy dispersion X-ray analysis (EDAX). From XRD analysis it is inferred that the obtained CdS films have highly orientated hexagonal structure with the preferential orientation along (002) plane. The optical characterization raveled that the films are highly transparent (60%–80%) in the visible region. From TEM analysis it has been observed that the inter planner spacing for CdS thin film is ∼0.31 nm and average crystallite size is 7–8 nm. The EDAX data revealed nearly stoichiometric characteristics of the CdS thin films. The SEM analysis showed that CdS thin films are smooth, homogeneous and uniform without cracks with randomly oriented spherical nanocrystallites. The CdS thin films have very high transmission in the range 600–1200 nm with the band gap >2.54 eV. The purpose of the present study is to develop window/buffer layer for CZTS solar cells

Structural and morphological properties of electrochemically deposited CdTe thin films

In present report, p-type CdTe semiconductor thin films were grown directly on transparent conductive Fluorine-doped SnO2-coated (FTO) glass substrates using three-electrode electrodeposition technique. The whole work carried out at ambient condition. Structural studies reveal that films are possessing cubic zinc blend crystal structure. The growth mechanism of CdTe nanostructures is revealed by investigating the cyclic voltammetry analysis. Morphological characterization demonstrates high-purity, uniform and well covered CdTe thin film over FTO glass substrate. The Hot probe experiment confirmed the p-type semiconducting behavior of CdTe thin films. The current investigation provides a novel approach in synthesis of p-type CdTe nanostructure, without any post annealing or surface treatment, for the direct fabrication of semiconductor sensitized solar cells

Structural and morphological properties of electrochemically deposited CdTe thin films

In present report, p-type CdTe semiconductor thin films were grown directly on transparent conductive Fluorine-doped SnO2-coated (FTO) glass substrates using three-electrode electrodeposition technique. The whole work carried out at ambient condition. Structural studies reveal that films are possessing cubic zinc blend crystal structure. The growth mechanism of CdTe nanostructures is revealed by investigating the cyclic voltammetry analysis. Morphological characterization demonstrates high-purity, uniform and well covered CdTe thin film over FTO glass substrate. The Hot probe experiment confirmed the p-type semiconducting behavior of CdTe thin films. The current investigation provides a novel approach in synthesis of p-type CdTe nanostructure, without any post annealing or surface treatment, for the direct fabrication of semiconductor sensitized solar cells

Development And Validation For Simultaneous Estimation Of Telmisartan And Hydro-chlorothiazide In Bulk Drug And Pharmaceu-tical Dosage Form By Uv- Spectrophotometry

A simple, accurate and precise simultaneous analytical method has been developed for simultaneous determination of Telmisartan and Hydrochlorothiazide in bulk drug and tablet dosage form. The wavelength selected for these drugs were 295.5 nm and 273.0 nm respectively. The linearity at selected wavelength lies between 10-90 µg/ml for Telmisartan and 5-60 µg/ml for Hydrochlorothiazide. The concentrations of these drugs were evaluated in laboratory mixture of reference standard and different marketed formulation. Recovery studies confirmed the accuracy of proposed method. Precision of the method was found as the values within acceptable limit. Thus the proposed method and results were validated as per ICH guidelines. Statistical analysis proves that the method is reproducible and selective for the simultaneous estimation of Telmisartan and Hydrochlorothiazide

The impact of structural bioinformatics tools and resources on SARS-CoV-2 research and therapeutic strategies.

SARS-CoV-2 is the causative agent of COVID-19, the ongoing global pandemic. It has posed a worldwide challenge to human health as no effective treatment is currently available to combat the disease. Its severity has led to unprecedented collaborative initiatives for therapeutic solutions against COVID-19. Studies resorting to structure-based drug design for COVID-19 are plethoric and show good promise. Structural biology provides key insights into 3D structures, critical residues/mutations in SARS-CoV-2 proteins, implicated in infectivity, molecular recognition and susceptibility to a broad range of host species. The detailed understanding of viral proteins and their complexes with host receptors and candidate epitope/lead compounds is the key to developing a structure-guided therapeutic design. Since the discovery of SARS-CoV-2, several structures of its proteins have been determined experimentally at an unprecedented speed and deposited in the Protein Data Bank. Further, specialized structural bioinformatics tools and resources have been developed for theoretical models, data on protein dynamics from computer simulations, impact of variants/mutations and molecular therapeutics. Here, we provide an overview of ongoing efforts on developing structural bioinformatics tools and resources for COVID-19 research. We also discuss the impact of these resources and structure-based studies, to understand various aspects of SARS-CoV-2 infection and therapeutic development. These include (i) understanding differences between SARS-CoV-2 and SARS-CoV, leading to increased infectivity of SARS-CoV-2, (ii) deciphering key residues in the SARS-CoV-2 involved in receptor-antibody recognition, (iii) analysis of variants in host proteins that affect host susceptibility to infection and (iv) analyses facilitating structure-based drug and vaccine design against SARS-CoV-2