Colloidal synthesis and characterization of Bi2S3 nanoparticles for photovoltaic applications

Bismuth sulfide is a promising n-type semiconductor for solar energy conversion. We have explored the colloidal synthesis of Bi2S3 nanocrystals, with the aim of employing them in the fabrication of solution-processable solar cells and to replace toxic heavy metals chalcogenides like PbS or CdS, that are currently employed in such devices. We compare different methods to obtain Bi2S3 colloidal quantum dots, including the use of environmentally benign reactants, through organometallic synthesis. Different sizes and shapes were obtained according to the synthesis parameters and the growth process has been rationalized by comparing the predicted morphology with systematic physical-chemistry characterization of nanocrystals by X-ray diffraction, FT-IR spectroscopy, Transmission Electron Microscopy (TEM)

Clinical Features, Cardiovascular Risk Profile, and Therapeutic Trajectories of Patients with Type 2 Diabetes Candidate for Oral Semaglutide Therapy in the Italian Specialist Care

Introduction: This study aimed to address therapeutic inertia in the management of type 2 diabetes (T2D) by investigating the potential of early treatment with oral semaglutide. Methods: A cross-sectional survey was conducted between October 2021 and April 2022 among specialists treating individuals with T2D. A scientific committee designed a data collection form covering demographics, cardiovascular risk, glucose control metrics, ongoing therapies, and physician judgments on treatment appropriateness. Participants completed anonymous patient questionnaires reflecting routine clinical encounters. The preferred therapeutic regimen for each patient was also identified. Results: The analysis was conducted on 4449 patients initiating oral semaglutide. The population had a relatively short disease duration (42%  60% of patients, and more often than sitagliptin or empagliflozin. Conclusion: The study supports the potential of early implementation of oral semaglutide as a strategy to overcome therapeutic inertia and enhance T2D management

Linewidth behavior of the A1g Raman phonon in CdxHg1-xI2 solid solution

The behavior of the A1g phonon line in CdxHg1-xI2 (with 0<x<0.38) solid solution has been investigated by Raman spectroscopy between 20 and 300 K. At room temperature, the A1g linewidth unexpectedly decreases as the cadmium concentration is increased; at low temperature, the more conventional opposite trend is observed. By taking into account a variation of the final density of states in which the A1g phonon decays, a convincing explanation of the experimental results is given. In addition, useful information on the behavior of the boundary LO(X) and/or LA(X) phonons in the solid solution can be extracted

Anharmonic mixing between two phonons in red mercury iodide

With use of Raman spectroscopy we have investigated the anharmonic mixing between two optical phonons of Eg symmetry in red mercury iodide. By taking into account the presence of several decay channels contributing to phonon lifetime, the experimental line-shape anomalies due to mode coupling have been reproduced with good accuracy. The temperature behavior of the anharmonic interaction is in agreement with theory

Properties of the electron-hole plasma in GaAs-(Ga,Al)As quantum wells: The influence of the finite well width

Photoluminescence spectra of the electron-hole plasma confined in GaAs-(Ga,Al)As quantum wells are presented. The spectra have been successfully fitted using a single-plasmon pole approximation. The results clearly show that the band-gap reduction Eg(w) depends on the width w of the well and is smaller than in a strictly two-dimensional plasma. Further, theoretical estimations of Eg(w) are in good agreement with our experimental results

The influence of temperature on the single-particle self-energy in a quasi two dimensional electron-hole plasma

The band gap reduction and the spectral broadening of the single particle states for a neutral electron-hole plasma confined in a GaAs/(Ga,Al)As quantum well are calculated in the full random phase approximation. The electrons and holes are assumed to populate the lowest subbands only. In particular we found that the temperature dependence of the band gap shrinkage is influenced by the broadening of the single particle states. The theoretical results compare reasonably well with the available experimental data

Many-body effects in the electron-hole plasma confined in GaAs-(GaAl)As quantum wells

Two-beam transmission and photoluminescence spectra of GaAs-(GaAl)As multiple quantum wells are presented. The spectra are studied as a function of the electron-hole (e-h) pair density. At low and with increasing density a blue-shift of the lowest exciton line is found. At densities above the Mott value, the band gap reduction depends on the width of the well and is much smaller than in a strictly two-dimensional e-h plasma. Further, even in a relatively dense plasma the excitonic enhancement factor differs strongly from unity, though it depends only weakly on the energy