A Redox-Active Ionic Liquid Surface Treatment for Healing CsPbBr Nanocrystals.

Additive engineering of lead halide perovskites has been a successful strategy for reducing a variety of deleterious defect types. Ionic liquids (ILs) are a unique group of such additives that have been used to passivate halide vacancies in both bulk lead halide perovskites and their colloidal nanocrystal analogues. Herein, we expand the types of defects that can be addressed through IL treatments in CsPbBr nanocrystals with a novel phosphonium tribromide IL that heals metallic lead surface defects through redox chemistry.

Disequilibrating azobenzenes by visible-light sensitization under confinement.

Photoisomerization of azobenzenes from their stable isomer to the metastable state is the basis of numerous applications of these molecules. However, this reaction typically requires ultraviolet light, which limits applicability. In this study, we introduce disequilibration by sensitization under confinement (DESC), a supramolecular approach to induce the -to- isomerization by using light of a desired color, including red.

The surface chemistry of ionic liquid-treated CsPbBr3 quantum dots.

The power conversion efficiencies of lead halide perovskite thin film solar cells have surged in the short time since their inception. Compounds, such as ionic liquids (ILs), have been explored as chemical additives and interface modifiers in perovskite solar cells, contributing to the rapid increase in cell efficiencies. However, due to the small surface area-to-volume ratio of the large grained polycrystalline halide perovskite films, an atomistic understanding of the interaction between ILs and perovskite surfaces is limited.

Validation of the French version of the Global Functioning: Social and Global Functioning: Role Scales in adolescents and young adults seeking help in early intervention clinics.

Aim: Social and role functioning impairments characterize patients along the schizophrenia spectrum, but the existing evaluations tools do not specifically address younger population issues. The Global Functioning Social (GF:S) and Global Functioning Role (GF:R) scales have been specifically designed for that purpose. The aim of this study is to establish the reliability and concurrent validity of the French version of GF:S and GF:R scales.

Directing the Morphology, Packing, and Properties of Chiral Metal-Organic Frameworks by Cation Exchange.

We show that metal-organic frameworks, based on tetrahedral pyridyl ligands, can be used as a morphological and structural template to form a series of isostructural crystals having different metal ions and properties. An iterative crystal-to-crystal conversion has been demonstrated by consecutive cation exchanges. The primary manganese-based crystals are characterized by an uncommon space group (P622).

Resolving the Controversy in Biexciton Binding Energy of Cesium Lead Halide Perovskite Nanocrystals through Heralded Single-Particle Spectroscopy.

Understanding exciton-exciton interaction in multiply excited nanocrystals is crucial to their utilization as functional materials. Yet, for lead halide perovskite nanocrystals, which are promising candidates for nanocrystal-based technologies, numerous contradicting values have been reported for the strength and sign of their exciton-exciton interaction. In this work, we unambiguously determine the biexciton binding energy in single cesium lead halide perovskite nanocrystals at room temperature.

Effect of Surface Ligands in Perovskite Nanocrystals: Extending in and Reaching out.

ConspectusThe rediscovery of the halide perovskite class of compounds and, in particular, the organic and inorganic lead halide perovskite (LHP) materials and lead-free derivatives has reached remarkable landmarks in numerous applications. First among these is the field of photovoltaics, which is at the core of today's environmental sustainability efforts. Indeed, these efforts have born fruit, reaching to date a remarkable power conversion efficiency of 25.

Growth-Etch Metal-Organic Chemical Vapor Deposition Approach of WS Atomic Layers.

Metal-organic chemical vapor deposition (MOCVD) is one of the main methodologies used for thin-film fabrication in the semiconductor industry today and is considered one of the most promising routes to achieve large-scale and high-quality 2D transition metal dichalcogenides (TMDCs). However, if special measures are not taken, MOCVD suffers from some serious drawbacks, such as small domain size and carbon contamination, resulting in poor optical and crystal quality, which may inhibit its implementation for the large-scale fabrication of atomic-thin semiconductors. Here we present a growth-etch MOCVD (GE-MOCVD) methodology, in which a small amount of water vapor is introduced during the growth, while the precursors are delivered in pulses.

Predicting the individual risk of psychosis conversion in at-risk mental state (ARMS): a multivariate model reveals the influence of nonpsychotic prodromal symptoms.

To improve the prediction of the individual risk of conversion to psychosis in UHR subjects, by considering all CAARMS' symptoms at first presentation and using a multivariate machine learning method known as logistic regression with Elastic-net shrinkage. 46 young individuals who sought help from the specialized outpatient unit at Sainte-Anne hospital and who met CAARMS criteria for UHR were assessed, among whom 27 were reassessed at follow-up (22.4 ± 6.

Band alignment and charge transfer in CsPbBr-CdSe nanoplatelet hybrids coupled by molecular linkers.

Formation of a p-n junction-like with a large built-in field is demonstrated at the nanoscale, using two types of semiconducting nanoparticles, CsPbBr nanocrystals and CdSe nanoplatelets, capped with molecular linkers. By exploiting chemical recognition of the capping molecules, the two types of nanoparticles are brought into mutual contact, thus initiating spontaneous charge transfer and the formation of a strong junction field. Depending on the choice of capping molecules, the magnitude of the latter field is shown to vary in a broad range, corresponding to an interface potential step as large as ∼1 eV.

PbS quantum dots as additives in methylammonium halide perovskite solar cells: the effect of quantum dot capping.

Colloidal PbS quantum dots (QDs) have been successfully employed as additives in halide perovskite solar cells (PSCs) acting as nucleation centers in the perovskite crystallization process. For this strategy, the surface functionalization of the QDs, controlled the use of different capping ligands, is likely of key importance. In this work, we examine the influence of the PbS QD capping on the photovoltaic performance of methylammonium lead iodide PSCs.

Gender differences of patients at-risk for psychosis regarding symptomatology, drug use, comorbidity and functioning - Results from the EU-GEI study.

Background: Gender differences in symptomatology in chronic schizophrenia and first episode psychosis patients have often been reported. However, little is known about gender differences in those at risk of psychotic disorders. This study investigated gender differences in symptomatology, drug use, comorbidity (i.

Individual factors influencing the duration of untreated psychosis.

Aim: Duration of untreated psychosis (DUP), or the time between onset of psychosis and treatment initiation, is a prognostic factor of schizophrenia. However, few studies evaluated the relative influence of individual-related factors on this duration. The objective of this study was to evaluate the influence of socio-demographic, clinical and cannabis use on DUP.

The C'JAAD: a French team for early intervention in psychosis in Paris.

Aim: The aim is to describe a centre operating in Paris that pioneers the early intervention for young people at the onset and at high risk of psychosis in France.

Methods: Comprehensive descriptive analysis of different clinical and service measures is used in describing the implementation of the C'JAAD (Evaluation Centre for Young Adults and Adolescents) using data from an ongoing prospective non-interventional research programme.

Results: Over a 2-year period, 151 patients were referred to the C'JAAD and included in the ICAAR research programme.

From dilute isovalent substitution to alloying in CdSeTe nanoplatelets.

Cadmium chalcogenide nanoplatelet (NPL) synthesis has recently witnessed a significant advance in the production of more elaborate structures such as core/shell and core/crown NPLs. However, controlled doping in these structures has proved difficult because of the restrictive synthetic conditions required for 2D anisotropic growth. Here, we explore the incorporation of tellurium (Te) within CdSe NPLs with Te concentrations ranging from doping to alloying.

Colloidal Double Quantum Dots.

Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods.

Photophysics of Voltage Increase by Photoinduced Dipole Layers in Sensitized Solar Cells.

Significant overpotentials between the sensitizer and both the electron and hole conductors hamper the performance of sensitized solar cells, leading to a reduced photovoltage. We show that by using properly designed type-II quantum dots (QDs) between the sensitizer and the hole conductor in thin absorber cells, it is possible to increase the open circuit voltage (Voc) by more than 100 mV. This increase is due to the formation of a photoinduced dipole (PID) layer.

[Assessment of mental states at risk of psychotic transition: validation of the French version of the CAARMS].

This article aims to present the validation study of the French version of the Comprehensive Assessment of at risk mental states (CAARMS), an interview that seeks to determine whether young adults criteria for at-risk (AR) mental states, or psychosis. We assessed 40 young subjects, 15 were considered as "prodromal" (Prd) and 10 as experiencing a first episode of psychosis (PEP) by our expert clinician at the center - centre d'évaluation des jeunes adultes et adolescents, University Hospital Centre, Paris - and 15 were healthy controls matched for age and sex. When assessed with the CAARMS, 73 % (n=11) of the prodromal subjects reached the criteria for AR mental state, four subjects did not reach the criteria for AR, nor psychosis (P) and 100 % of the PEP reached the criteria for P.

Chronic persecutory delusion and autobiographical memories in patients with schizophrenia: a diary study.

Background: While chronic persecutory delusions are typically anchored into patients' everyday life situations, no investigation has ever looked at how situations associated with a feeling of persecution are recorded and later retrieved.

Method: a diary methodology combined with a recognition task involving ten patients with schizophrenia who presented chronic persecutory delusions and ten control participants. Diaries of everyday persecutory events (Pe) and non-persecutory events (nPe) were kept.

Subjects at Ultra High Risk for psychosis have 'heterogeneous' intellectual functioning profile: a multiple-case study.

In Ultra High Risk (UHR) studies, intellectual functioning is commonly assessed using premorbid IQ tools as a covariate. The aim of this study was to show that the use of the Wechsler Adult Intelligence Scale (WAIS) could yield accurate neuropsychological profiling and that an alternative approach such as a multiple-case study could be a more interesting way to isolate discrete cognitive processes in the early stage of illness. The studied population consisted of 198 adolescents and young adults (16-30 y.