Luminescence Properties of CZT Crystals in the Presence of Tellurium Inclusions

CZT is a widespread material for the realization of room temperature radiation detectors. The presence of defects and in particular secondary phases, like Te inclusions, represents nowadays a limit in the realization of high resolution devices. For the development of CZT detectors, in particular for high-flux applications, is very important to understand the role of deep levels, the influence of Te inclusions on the device performance and their correlations between Te inclusions and deep levels. Using a IR microscope recently developed at IMEM, it is possible to identify the 3D position of each inclusion in the bulk and reconstruct a 3D plot describing the spacial position of every inclusion. This permits to select a sigle inclusion in the sample, to place the inclusion very close to the surface (few microns) by etching the sample and hence to study the selected inclusion. In this way it is possible to perform photoluminescence and cathodoluminescence mapping in the inclusion region and investigate the behavior of the crystal-inclusion interface. The correlation between the deep level emission acquired at the micro-scale and the presence of tellurium inclusion is discussed

Relazione sulle attivit? completate nel 4? semestre, periodo 20/09/2009-20/02/2010 del progetto 1

Secondo il piano temporale dettagliato del progetto gli obiettivi individuati nel semestre 20/08/2009-20/02/2010 sono: A.1.1: progetto preliminare di componenti termo-fotovoltaici A.4.1: progetto preliminare di caldaia termofotovoltaicaSecondo il piano temporale dettagliato del progetto gli obiettivi individuati nel semestre 20/08/2009-20/02/2010 sono: A.1.1: progetto preliminare di componenti termo-fotovoltaici A.4.1: progetto preliminare di caldaia termofotovoltaic

Results on MOVPE SiGeSn deposition for the monolithic integration of III-V and IV elements in multi-junction solar cells

Abstract In order to produce a step forward towards the monolithic integration of III-V and IV compounds in multijunction solar cells, a first assessment of SiGeSn deposition in a metal organic vapour phase epitaxy (MOVPE) chamber also used for III-V growth has been carried out. The study brings insights on several aspects of the MOVPE SiGeSn growth in order to get a better control of SiGeSn composition and to obtain epitaxial layers with improved morphology. In particular, it is shown that the gas source Si2H6 is more influenced by the growth temperature compared to GeH4 and SnCl4, moreover, its competition with SnCl4 makes it difficult to incorporate Si in SiGeSn, as SnCl4 partial pressure is increased. SiGeSn morphology is shown to be strongly dependent on temperature, As carry-over and growth rate. A new growth model is introduced in order to explain the importance of the adatom bond lengths in inhibiting tin segregation when SiGeSn is grown at relatively high growth temperatures (>480 °C). In order to investigate the photovoltaic behaviour of SiGeSn, a single-junction GaAs/InGaP/SiGeSn/Ge functional device has been manufactured and characterized by external quantum efficiency (EQE) and current-voltage measurements. The experimental and the simulated EQE show the higher absorption coefficient of SiGeSn with respect to Ge, which allows using SiGeSn layers with a thickness three times lower than Ge to produce the same photovoltaic current

Advanced CT imaging features reflect distinct tissue immune profiles and exhibit high prognostic impact on NSCLC

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Growth and characterization of red-green-blue cathodoluminescent ceramic films

Gd2O3 and Y2O3 films, respectively, doped with Eu3+, Tb3+, and Tm3+ have been grown by the electron beam physical vapor codeposition technique on optically polished quartz substrates. The film samples have been doped at different concentrations by the corresponding rare-earth oxides. The concentration range explored is from 0.9% to 9.8% on 18 samples. For each film sample an extended characterization has been performed by thin film-x-ray diffraction, scanning electron microscopy, energy dispersion spectroscopy, cathodoluminescence spectroscopy, and color coordinate analysis. Y2O3 films display the most intense red-green-blue (RGB) emission and their film morphology and structure are more compact and crystalline with respect to Gd2O3 monoclinic films. Eu3+ and Tb3+ doped Y2O3 films grow oriented along the (222) direction. The ratios between the intensities of the electric dipole and magnetic dipole transitions have been also evaluated. The blue emission of Tm3+ doped Gd2O3 is lacking in the dopant concentration range from 1.6% to 7.6%, whereas it is present in Tm3+ doped Y2O3 films, at approximately the same dopant concentration range (1.9%-9.8%). Commission Internationale de l'Eclairage plot of the color coordinates of all the RGB film samples has been reported together with the RGB phosphor standard used in cathodic ray tube TV screens

A study of the CdTe treatment with a Freon gas such as CHF2Cl

In order to obtain high efficiency CdS/CdTe solar cells, a CdTe heat treatment in a Cl-2 containing atmosphere is necessary. Normally, this treatment is done by depositing a CdCl2 thin film on top of CdTe and by heating the system in air at a fixed temperature. This step is disadvantageous in a large scale fabrication process because it involves the use of CdCl2 that it is difficult to be handled. We replaced this treatment by using a gas (HCF2Cl) that is stable, inert and not toxic at room temperature and eliminates the step of CdCl2 evaporation and subsequent chemical etching. (c) 2007 Elsevier B.V. All rights reserved

Competitive pathways in Pd-catalyzed synthesis of arylphenols

Novel developments are described, which have been achieved in the framework of the studies of sequential palladium-catalyzed reactions, involving palladacycle formation with norbornene or norbornadiene via aromatic CeH activation. The use of o-bromophenols as partners of iodobenzenes has led to ring formation after norbornene deinsertion, or to arylphenols, containing a pendant norbornenyl or norbornadienyl group or to vinylarylphenols. The availability of a reductive elimination step drives the reaction course toward a preferential product

Authentication of ready-to-eat anchovy products sold on the Italian market by BLAST analysis of a highly informative cytochrome b gene fragment

18 pages, 4 figures.In this study, 111 ready-to-eat anchovy products were collected on the Italian market. The products were molecularly identified through a BLAST analysis of a highly informative cytb fragment amplified by a newly designed primer pair for the genus Engraulis spp. and the mislabelling rate was assessed. In addition, the labels were analysed in the light of the current EU law. Despite only one mislabelling case was observed (mislabelling rate 0.9%), which involved the substitution of the European anchovy (Engraulis encrasicolus) with the low-valuable Peruvian/Chilean anchoveta (Engraulis ringens), the molecular technique developed in this study was proved as suitable tool for detecting species in processed anchovy products. It could be therefore applied to carry out more extensive EU survey aimed at evaluating the mislabelling rate of such products, still poorly covered by a targeted and clear legislation system.Peer reviewe

Characteristics of the caregiver in mental health: Stress and strain

Background: after the closing of psychiatric hospitals caring for someone with a mental illness has become a family endeavor. the aim of this study was to assess levels of depression, anxiety and distress experienced by caregivers and the correlation between the intensity of these symptoms and the emotional burden perceived. MethODs: Participants were recruited from September 2015 until February 2016. caregivers' strain, depression, anxiety and distress were evaluated through the administration of FsQ-sF and Dass-21; vGF assessed patients' global capabilities. resULts: Forty percent of caregivers falls within the risk area "strongly recommended", 35% within the risk area "urgent" of FsQ-sF. scores are higher in females than in males. Personality Disorders evokes the greatest emotional impact in caregivers, followed by psychotic disorders and mood and anxiety disorders. the comparison between the mean score of the three Dass-21 subscales highlight the highest value in "stress" category, followed by "depression" and "anxiety". a positive correlation between FsQ-sF scores and Dass-21 subscales scores is observed (0.3<P<0.7); the highest correlation observed is between FsQ-sF score and "stress" subscale (P=0.42). a positive correlation between FsQ-sF scores and Dass-21 stress subscale emerges. the lowest value belongs to the category of psychotic disorders and there is a negative correlation between this value and the emotional burden and anxiety experienced by caregivers. cOncLUsiOns: Women with a medium-low level of education, usually retired, are the main relative involved in patient care. Future research could focus on factors causing psychological distress among caregivers and propose valid coping strategies and support