Photoluminescence of Chemically and Electrically Doped Two-Dimensional Monolayer Semiconductors.

Two-dimensional (2D) transition metal dichalcogenide (TMDC) monolayers exhibit unique physical properties, such as self-terminating surfaces, a direct bandgap, and near-unity photoluminescence (PL) quantum yield (QY), which make them attractive for electronic and optoelectronic applications. Surface charge transfer has been widely used as a technique to control the concentration of free charge in 2D semiconductors, but its estimation and the impact on the optoelectronic properties of the material remain a challenge. In this work, we investigate the optical properties of a WS monolayer under three different doping approaches: benzyl viologen (BV), potassium (K), and electrostatic doping.

Corticosteroids in oncology: Use, overuse, indications, contraindications. An Italian Association of Medical Oncology (AIOM)/ Italian Association of Medical Diabetologists (AMD)/ Italian Society of Endocrinology (SIE)/ Italian Society of Pharmacology (SIF) multidisciplinary consensus position paper.

Corticosteroids (CSs) are widely used in oncology, presenting several different indications. They are useful for induction of apoptosis in hematological neoplasms, for management of anaphylaxis and cytokine release/hypersensitivity reaction and for the symptomatic treatment of many tumour- and treatment-related complications. If the employment of CSs in the oncological setting results in several benefits for patients and satisfaction for clinicians, on the other hand, many potential adverse events (AEs), both during treatment and after withdrawal of CSs, as well as the duality of the effects of these compounds in oncology, recommend being cautious in clinical practice.

Metabolic disorders and gastroenteropancreatic-neuroendocrine tumors (GEP-NETs): How do they influence each other? An Italian Association of Medical Oncology (AIOM)/ Italian Association of Medical Diabetologists (AMD)/ Italian Society of Endocrinology (SIE)/ Italian Society of Pharmacology (SIF) multidisciplinary consensus position paper.

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a heterogeneous group of malignancies derived from neuroendocrine cells that can occur anywhere along the gastrointestinal tract. GEP-NETs incidence has been steadily increasing over the past decades, in parallel with the increasing incidence of the metabolic syndrome (MetS). It is not yet fully known whether the MetS components (such as obesity, dyslipidemia and type 2 diabetes) could be involved in the etiology of GEP-NETs or could influence their outcomes.

Expected and paradoxical effects of obesity on cancer treatment response.

Obesity, whose prevalence is pandemic and continuing to increase, is a major preventable and modifiable risk factor for diabetes and cardiovascular diseases, as well as for cancer. Furthermore, epidemiological studies have shown that obesity is a negative independent prognostic factor for several oncological outcomes, including overall and cancer-specific survival, for several site-specific cancers as well as for all cancers combined. Yet, a recently growing body of evidence suggests that sometimes overweight and obesity may associate with better outcomes, and that immunotherapy may show improved response among obese patients compared with patients with a normal weight.

Nutritional status and follicular-derived thyroid cancer: An update.

The incidence of differentiated thyroid cancer has been increasing in the last decades all over the world. Such a steady growth cannot be entirely attributable to more intensive thyroid nodule screening and more sensitive diagnostic procedures. Several environmental factors have changed with sufficient rapidity in the same time frame and may represent credible candidates for this increase.

Composition-Controlled Atomic Layer Deposition of Phase-Change Memories and Ovonic Threshold Switches with High Performance.

Chalcogenide compounds are the main characters in a revolution in electronic memories. These materials are used to produce ultrafast ovonic threshold switches (OTSs) with good selectivity and moderate leakage current and phase-change memories (PCMs) with excellent endurance and short read/write times when compared with state-of-the-art flash-NANDs. The combination of these two electrical elements is used to fabricate nonvolatile memory arrays with a write/access time orders of magnitude shorter than that of state-of-the-art flash-NANDs.

The Electrical and Optical Properties of Organometal Halide Perovskites Relevant to Optoelectronic Performance.

Organometal halide perovskites are under intense study for use in optoelectronics. Methylammonium and formamidinium lead iodide show impressive performance as photovoltaic materials; a premise that has spurred investigations into light-emitting devices and photodetectors. Herein, the optical and electrical material properties of organometal halide perovskites are reviewed.

Photovoltage field-effect transistors.

The detection of infrared radiation enables night vision, health monitoring, optical communications and three-dimensional object recognition. Silicon is widely used in modern electronics, but its electronic bandgap prevents the detection of light at wavelengths longer than about 1,100 nanometres. It is therefore of interest to extend the performance of silicon photodetectors into the infrared spectrum, beyond the bandgap of silicon.

Engineering of CH3 NH3 PbI3 Perovskite Crystals by Alloying Large Organic Cations for Enhanced Thermal Stability and Transport Properties.

The number of studies on organic-inorganic hybrid perovskites has soared in recent years. However, the majority of hybrid perovskites under investigation are based on a limited number of organic cations of suitable sizes, such as methylammonium and formamidinium. These small cations easily fit into the perovskite's three-dimensional (3D) lead halide framework to produce semiconductors with excellent charge transport properties.

Fast and Sensitive Solution-Processed Visible-Blind Perovskite UV Photodetectors.

The first visible-blind UV photodetector based on MAPbCl3 integrated on a substrate exhibits excellent performance, with responsivities reaching 18 A W(-1) below 400 nm and imaging-compatible response times of 1 ms. This is achieved by using substrate-integrated single crystals, thus overcoming the severe limitations affecting thin films and offering a new application of efficient, solution-processed, visible-transparent perovskite optoelectronics.

The In-Gap Electronic State Spectrum of Methylammonium Lead Iodide Single-Crystal Perovskites.

The density of trap states within the bandgap of methylammonium lead iodide single crystals is investigated. Defect states close to both the conduction and valence bands are probed. Additionally, a comprehensive electronic characterization of crystals is carried out, including measurements of the electron and hole mobility, and the energy landscape (band diagram) at the surface.

Heterovalent Dopant Incorporation for Bandgap and Type Engineering of Perovskite Crystals.

Controllable doping of semiconductors is a fundamental technological requirement for electronic and optoelectronic devices. As intrinsic semiconductors, hybrid perovskites have so far been a phenomenal success in photovoltaics. The inability to dope these materials heterovalently (or aliovalently) has greatly limited their wider utilizations in electronics.

Planar-integrated single-crystalline perovskite photodetectors.

Hybrid perovskites are promising semiconductors for optoelectronic applications. However, they suffer from morphological disorder that limits their optoelectronic properties and, ultimately, device performance. Recently, perovskite single crystals have been shown to overcome this problem and exhibit impressive improvements: low trap density, low intrinsic carrier concentration, high mobility, and long diffusion length that outperform perovskite-based thin films.

The Silicon:Colloidal Quantum Dot Heterojunction.

A heterojunction between crystalline silicon and colloidal quantum dots (CQDs) is realized. A special interface modification is developed to overcome an inherent energetic band mismatch between the two semiconductors, and realize the efficient collection of infrared photocarriers generated in the CQD film. This junction is used to produce a sensitive near infrared photodetector.

Single-step fabrication of quantum funnels via centrifugal colloidal casting of nanoparticle films.

Centrifugal casting of composites and ceramics has been widely employed to improve the mechanical and thermal properties of functional materials. This powerful method has yet to be deployed in the context of nanoparticles--yet size-effect tuning of quantum dots is among their most distinctive and application-relevant features. Here we report the first gradient nanoparticle films to be constructed in a single step.

Solar cells. Low trap-state density and long carrier diffusion in organolead trihalide perovskite single crystals.

The fundamental properties and ultimate performance limits of organolead trihalide MAPbX3 (MA = CH3NH3(+); X = Br(-) or I(-)) perovskites remain obscured by extensive disorder in polycrystalline MAPbX3 films. We report an antisolvent vapor-assisted crystallization approach that enables us to create sizable crack-free MAPbX3 single crystals with volumes exceeding 100 cubic millimeters. These large single crystals enabled a detailed characterization of their optical and charge transport characteristics.

Photojunction field-effect transistor based on a colloidal quantum dot absorber channel layer.

The performance of photodetectors is judged via high responsivity, fast speed of response, and low background current. Many previously reported photodetectors based on size-tuned colloidal quantum dots (CQDs) have relied either on photodiodes, which, since they are primary photocarrier devices, lack gain; or photoconductors, which provide gain but at the expense of slow response (due to delayed charge carrier escape from sensitizing centers) and an inherent dark current vs responsivity trade-off. Here we report a photojunction field-effect transistor (photoJFET), which provides gain while breaking prior photoconductors' response/speed/dark current trade-off.

Air-stable n-type colloidal quantum dot solids.

Colloidal quantum dots (CQDs) offer promise in flexible electronics, light sensing and energy conversion. These applications rely on rectifying junctions that require the creation of high-quality CQD solids that are controllably n-type (electron-rich) or p-type (hole-rich). Unfortunately, n-type semiconductors made using soft matter are notoriously prone to oxidation within minutes of air exposure.

Doping control via molecularly engineered surface ligand coordination.

A means to control the net doping of a CQD solid is identified via the design of the bidentate ligand crosslinking the material. The strategy does not rely on implementing different atmospheres at different steps in device processing, but instead is a robust strategy implemented in a single processing ambient. We achieve an order of magnitude difference in doping that allows us to build a graded photovoltaic device and maintain high current and voltage at maximum power-point conditions.

Graded doping for enhanced colloidal quantum dot photovoltaics.

A novel approach to improving all-inorganic colloidal quantum dot (CQD) homojunction solar cells by engineering the doping spatial profile to produce a doping gradient within the n-type absorber is presented. The doping gradient greatly improves carrier collection and enhances the voltages attainable by the device, leading to a 1 power point power conversion efficiency (PCE) improvement over previous inorganic CQD solar cells.

Gender-dependent association of type 2 diabetes with the vasoactive intestinal peptide receptor 1.

Type 2 diabetes is characterized by an inadequate pancreatic beta-cell response to the progressive insulin resistance. Its pathogenesis is complex and has been connected with a state of preclinical chronic inflammation. Vasoactive intestinal peptide (VIP) and its receptors play a relevant role in the homeostasis of insulin secretion as well as in the control of inflammation.