Growth techniques used to develop CDS/CDTE thin film solar cells: a review

The method used to grow thin film CdS/CdTe solar cells has been described. Electronic material layers usually grow in three different modes; layer-by-layer growth mode, layer and cluster growth mode (Stransky-Krastanov) and cluster formation growth mode. Techniques such as molecular beam epitaxy (MBE), metal organic chemical vapour deposition (MOCVD) called melt growth or Bridgman are well known as high quality semiconductor growth techniques. One of the limitations of these techniques is the inability for manufacturing macro-electronic devices (~area 1m2) such as photovoltaic (PV) panels and large area display devices. To grow large area thin film (semiconductors), growth techniques such as close space sublimation (CSS), electrodeposition (ED), sputtering, spray pyrolysis etcetera have been tested and employed. This paper reviews in depth most of these techniques with more emphasis on the electrodeposition method because of it is simplicity and low cost.Keywords: Growth Techniques, CdS, CdTe, Thin Films, Solar Cells

Determination of elemental constituents for three herbal plants that are traditionally used to cure cancer

Elemental constituents of fresh leaves of the three herbal plants used traditionally for treatment of cancer namely: Guera Senegalense, Boswellia and Mangifera Indica were analyzed. Results show that all the three samples contain the highest amounts of calcium in parts per million (Guiera Senegalensis 5991 ppm, Boswellia 9413 ppm and Mangifera Indica 2405 ppm) as compared to other constituents. Further studies reveal that presence of calcium in appreciable amount within the metabolic system of human being helps to reduce the risk of cancer and related ailments. Other benefits of calcium in man include strengthening bones and teeth.Keywords: Herbal Medicine, Cancer, Constituents, Carcinoge

Optimisation of CdTe electrodeposition voltage for development of CdS/CdTe solar cells

Cadmium telluride (CdTe) thin films have been deposited on glass/conducting glass (FTO) substrates using low-cost two electrode system and aqueous electrodeposition method. The glass/FTO substrates were used to grow the CdTe layers at different deposition voltages. The structural, electrical, optical and morphological properties of the resulting films have been characterized using X-ray diffraction (XRD), Photoelectrochemical (PEC) cell measurements, optical absorption spectroscopy and Scanning Electron Microscopy (SEM). The XRD results indicate that at voltages less than or higher than 1.576 V, crystallinity is poor due to presence of two phases. When CdTe is grown at 1.576 V, the composition is stoichiometric, and the (111) peak has the highest intensity in the XRD diffractogram indicating a high degree of crystallinity. SEM studies showed that all layers had pin-holes and gaps between the grains. These openings seem to be more common in the samples grown at voltages away from the stoichiometric voltage (1.576 V). The linear I–V curves of glass/FTO/CdS/CdTe/Au structures fabricated using stoichiometric CdTe showed efficiency of 10.1 % under AM 1.5 illuminatio

Inflammatory myofibroblastic tumor after lung transplant-A rare and aggressive complication. A case report.

Introduction Malignant diseases are well-known complications after lung transplantation (LT). Among these, inflammatory myofibroblastic tumor (IMT) is a rare neoplasm with a not well-known and often aggressive biological behavior. Material and Methods We hereby describe 2 cases of cystic fibrosis patients who underwent bilateral sequential LT (BSLT) complicated by IMT. Results A 26-year-old man presented a right endobronchial lesion 6 months after BSLT. Two consecutive fiber bronchoscopic biopsies showed granulation tissue. For the persistent lesion growth, the patient underwent a transthoracic biopsy showing histologic diagnosis of IMT. Therefore, he underwent to right pneumonectomy that was unfortunately complicated after 6 months with a late bronchopleural fistula and empyema with exitus 6 months later. A 31-year-old woman 1 year after BSLT presented with a left voluminous pleural-parenchymal lesion; the histologic examination after biopsy revealed an IMT. She underwent a removal of the lesion with a macroscopic R0 resection. Histologic, immunophenotypic, and cytogenetic examinations showed a strong overexpression of anaplastic lymphoma kinase requiring biological adjuvant therapies; however, the patient refused it. Four years later, she presented a recurrence treated with debulking procedure and adjuvant radiotherapy. At last follow-up, the patient was alive with stable disease and optimal graft function. Conclusions Although IMT is a rare complication after lung transplant, to obtain a careful diagnosis, an early and aggressive treatment is mandatory

Electro-plating and characterisation of cadmium sulphide thin films using ammonium thiosulphate as the sulphur source

Cadmium sulphide (CdS) thin films have been successfully prepared from an aqueous electrolyte bath containing CdCl2 and ammonium thiosulphate ((NH4)2S2O3) using electrodeposition technique. The structural, compositional, optical, morphological and electrical properties of these thin films have been characterized using X-ray diffraction (XRD), Raman spectroscopy, energy dispersive X-ray spectroscopy, UV–Vis spectrophotometry, scanning electron microscopy (SEM), atomic force microscopy (AFM), photoelectrochemical cell and D.C. current–voltage (I–V) measurements. The optimum deposition cathodic potential has been observed at 1,455 mV, in a 2-electrode system with respect to carbon anode. Structural analysis using XRD shows a mixture of hexagonal and cubic phases in the as-deposited CdS samples and a phase transformation to the hexagonal structure occurred after heat treatment at 400 °C for 20 min. Optical studies demonstrate an improvement in the band edge, producing 2.42 eV for the band gap of the films after heat treatment. The heat treated CdS thin films show better transmission for wavelengths longer than 500 nm. SEM and AFM show that the heat-treated samples are more uniform, smoother and have larger grain size. Electrical studies confirm that the CdS thin films have n-type electrical conductivity and heat treated CdS thin films have resistivities of the order of 105 Ω cm

Usefulness of bronchoalveolar lavage in suspect COVID-19 repeatedly negative swab test and interstitial lung disease

The diagnosis of coronavirus disease 2019 (COVID-19) relies on nasopharyngeal swab, which shows a 20–30% risk of false negativity [1]. Bronchoalveolar lavage (BAL) is reported to be useful in patients with pulmonary interstitial infiltrates on high-resolution computed tomography (HRCT). We investigated the usefulness of BAL in symptomatic patients with positive HRCT and a repeatedly negative swab test (‘grey zone’)

Electrodeposition and characterisation of CdS thin films using thiourea precursor for application in solar cells

CdS thin films have been successfully electrodeposited on glass/FTO substrates using acidic and aqueous solution of CdCl2.xH2O and thiourea (SC(NH2)2). The electrodeposition of CdS thin films were carried out potentiostatically using a 2-electrode system. The prepared films were characterised using X-ray diffraction (XRD), Raman spectroscopy, Scanning electron microscopy (SEM), Atomic force microscopy (AFM), Photoelectrochemical (PEC) cell measurements, Electrical resistivity measurements and UV-Vis spectrophotometry to study their structural, compositional, morphological, electrical and optical properties, respectively. The structural studies show that the as-deposited and annealed CdS layers are polycrystalline with hexagonal crystal structure and preferentially oriented along (200) planes. The optical studies indicate that the ED-CdS layers have direct bandgaps in the range (2.53-2.58) eV for the as-deposited and (2.42-2.48) eV after annealing at 400oC for 20 minutes in air. The morphological studies show the good coverage of the FTO surface by the CdS grains. The average grain sizes for the as-deposited and annealed layers were in the range (60-225) nm. These grains or clusters are made out of smaller nano crystallites with the sizes in the range ~(11-33) nm. The electrical resistivity shows reduction as thickness increases. The resistivity values for the as-deposited and annealed layers were in the range (0.82-4.92)×105 Ωcm. The optimum growth voltage for the CdS thin films was found to be at the cathodic potential of 797 mV with respect to the graphite anode. No visible precipitations of elemental S or CdS particles were observed in the deposition electrolyte showing a stable bath using thiourea during the growth

Selection of Candidates for Lung Transplantation: The First Italian Consensus Statement

Lung transplantation is a well-established treatment for selected patients with advanced chronic respiratory insufficiency. Recognizing those patients with end-stage lung disease who might benefit from lung transplantation is a crucial task. Considering the presence of inadequate evidence-based practice, international and national scientific societies provided consensus opinions regarding the appropriate timing of listing. The Study Group for Thoracic Organs Transplantation (branch of the Italian Society for Organs Transplantation) promoted and realized a Delphi conference among the Italian lung transplantation centers to provide guidance to clinical practice based on international recommendations. The experts from the nine Italian centers completed two rounds of standardized questionnaires (answer rate, 100%): 42 statements received a consensus â\u89¥80%. The selected statements presented in this article are intended to assist Italian clinicians in selecting patients for lung transplantation