Intercavity polariton slows down dynamics in strongly coupled cavities.

Band engineering stands as an efficient route to induce strongly correlated quantum many-body phenomena. Besides inspiring analogies among diverse physical fields, tuning on demand the group velocity is highly attractive in photonics because it allows unconventional flows of light. Λ-schemes offer a route to control the propagation of light in a lattice-free configurations, enabling exotic phases such as slow-light and allowing for highly optical non-linear systems. Here, we realize room-temperature intercavity Frenkel polaritons excited across two strongly coupled cavities. We demonstrate the formation of a tuneable heavy-polariton, akin to slow light, appearing in the absence of a periodic in-plane potential. Our photonic architecture based on a simple three-level scheme enables the unique spatial segregation of photons and excitons in different cavities and maintains a balanced degree of mixing between them. This unveils a dynamical competition between many-body scattering processes and the underlying polariton nature which leads to an increased fluorescence lifetime. The intercavity polariton features are further revealed under appropriate resonant pumping, where we observe suppression of the polariton fluorescence intensity.

Surfactant-tail control of CsPbBr3 nanocrystal morphology.

CsPbBr3 nanocrystals (NCs) are promising optoelectronic and catalytic materials. Manipulating their morphology can improve their properties and stability. In this work, an alkene-derived zwitterionic ligand was used to control the morphology of CsPbBr3 NCs to yield the highly unusual rhombicuboctahedron morphology, showcasing the first example of a surfactant-tail controlled growth.

Zwitterionic "Solutions" for Reversible CO2 Capture.

The zwitterions resulting from the covalent attachment of 3- or 4-hydroxy benzene to the 1,3-dimethylimidazolium cation represent basic compounds (pKa of 8.68 and 8.99 in aqueous solutions, respectively) that chemisorb in aqueous solutions 0.58 mol/mol of carbon dioxide at 1.3 bar (absolute) and 40 °C. Equimolar amounts of chemisorbed CO2 in these solutions are obtained at 10 bar and 40 °C. Chemisorption takes place through the formation of bicarbonate in the aqueous solution using imidazolium-containing phenolate. CO2 is liberated by simple pressure relief and heating, regenerating the base. The enthalpy of absorption was estimated to be -38 kJ/mol, which is about 30 % lower than the enthalpy of industrially employed aqueous solutions of MDEA (estimated at -53 kJ/mol using the same experimental apparatus). The physisorption of CO2 becomes relevant at higher pressures (>10 bar) in these aqueous solutions. Combined physio- and chemisorption of up to 1.3 mol/mol at 40 bar and 40 °C can be attained with these aqueous zwitterionic solutions that are thermally stable and can be recycled at least 20 times.

Early intestinal complications following pancreas transplantation: lessons learned from over 300 cases - a retrospective single-center study.

Enteric complications remain a major cause of morbidity in the post-transplant period of pancreas transplantation despite improvements surgical technique. The aim of this single-center study was to analyze retrospectively the early intestinal complications and their potential relation with vascular events. From 2000 to 2016, 337 pancreas transplants were performed with systemic venous drainage. For exocrine secretion, intestinal drainage was done with hand-sewn anastomosis duodenojejunostomy. Twenty-three patients (6.8%) had early intestinal complications. Median age was 39 years (male: 65.2%). Median cold ischemia time was 11 h [IQR: 9-12.4]. Intestinal complications were intestinal obstruction (n = 7); paralytic ileus (n = 5); intestinal fistula without anastomotic dehiscence (n = 3); ischemic graft duodenum (n = 3); dehiscence of duodenojejunostomy (n = 4); and anastomotic dehiscence in jejunum after pancreas transplantectomy (n = 1). Eighteen cases required relaparotomy: adhesiolysis (n = 6); repeated laparotomy without findings (n = 1); transplantectomy (n = 6); primary leak closure (n = 3); re-positioning of the graft (n = 1); and intestinal resection (n = 1). Of the intestinal complications, 4 were associated with vascular thrombosis, resulting in two pancreatic graft losses. Enteric drainage with duodenum-jejunum anastomosis is safe and feasible, with a low rate of intra-abdominal complications. Vascular thrombosis associated with intestinal complications presents a risk factor for the viability of pancreatic grafts, so prevention and early detection is vital.

Efficient Emission in Halide Layered Double Perovskites: The Role of Sb3+ Substitution in Cs4Cd1-xMnxBi2Cl12 Phosphors.

Layered double perovskites have the potential to further expand the vast space of optoelectronic properties and applications of halide perovskites. Among the ∼60 known members, to date only the ⟨111⟩-oriented layered double perovskites, Cs4Cd1-xMnxBi2Cl12, have shown efficient photoluminescence (PL). The replacement of Bi with Sb in these materials was investigated, resulting in two new families of layered inorganic perovskite alloys with full solubility. The first, Cs4Cd1-xMnxSb2Cl12, exhibits a PL emission at 605 nm ascribed to Mn2+ centers, with a maximum quantum yield of 28.5%. The second, Cs4Cd0.8Mn0.2(Sb1-yBiy)2Cl12, contains a fixed amount of Mn2+ and Cd2+ but variable Sb3+ and Bi3+ concentrations. We observed a decreased efficiency of the Cs4Cd1-xMnxSb2Cl12 family compared to that of Cs4Cd1-xMnxBi2Cl12, which was attributed to a decreased spin-orbit and Jahn-Teller couplings in Sb and the subsequent increased electronic delocalization. The present work lays out a roadmap to achieve high photoluminescence efficiencies in layered double perovskites.

Fluorometric detection of iodine by MIL-53(Al)-TDC.

The fluorescent properties of MIL-53(Al)-TDC are drastically changed due to the presence of iodine, even in small quantities, as a result of an energy transfer process from the host material (MIL-53(Al)-TDC) to the guest molecule (I2). While MIL-53(Al)-TDC's emission spectrum shows a weak and broad band, after I2 adsorption, it exhibits well-resolved and long-lasting emission lines, which could be exploited for iodine detection. Density Functional Theory periodical calculations demonstrated that in the most stable MIL-53(Al)-TDCI2 configuration, the I2 molecule is bonded mainly by an O-HI hydrogen bond. The QTAIM showed that other non-covalent interactions also provided stability to MIL-53(Al)-TDCI2. The electrostatic potential analysis indicated that the I2 molecule adsorption occurs by a combination of specific interactions with a strong electrostatic contribution and weak interactions. These results postulate fluorescent MIL-53(Al)-TDC as an efficient I2 detector (potentially for radioactive I2), using a simple fluorimetric test.

Confinement of H2O and EtOH to enhance CO2 capture in MIL-53(Al)-TDC.

EtOH sorption properties were investigated in MIL-53(Al)-TDC and found a strong interaction between EtOH and the MOF material (ΔHads = 69.6 kJ mol-1). CO2 capture was enhanced upon confining small amounts of H2O. Upon confining small amounts of EtOH however, the CO2 uptake was not improved. The difference in CO2 uptake with EtOH and H2O was rationalised using computational calculations. The analysis of the quantum theory of atoms in molecules (QTAIM) showed a covalent interaction between a MOF model and confined molecules (EtOH and H2O), and no difference in the hydrogen bonds between confined molecules and CO2.

A Direct Bandgap Copper-Antimony Halide Perovskite.

Since the establishment of perovskite solar cells (PSCs), there has been an intense search for alternative materials to replace lead and improve their stability toward moisture and light. As single-metal perovskite structures have yielded unsatisfactory performances, an alternative is the use of double perovskites that incorporate a combination of metals. To this day, only a handful of these compounds have been synthesized, but most of them have indirect bandgaps and/or do not have bandgaps energies well-suited for photovoltaic applications. Here we report the synthesis and characterization of a unique mixed metal ⟨111⟩-oriented layered perovskite, Cs4CuSb2Cl12 (1), that incorporates Cu2+ and Sb3+ into layers that are three octahedra thick (n = 3). In addition to being made of abundant and nontoxic elements, we show that this material behaves as a semiconductor with a direct bandgap of 1.0 eV and its conductivity is 1 order of magnitude greater than that of MAPbI3 (MA = methylammonium). Furthermore, 1 has high photo- and thermal-stability and is tolerant to humidity. We conclude that 1 is a promising material for photovoltaic applications and represents a new type of layered perovskite structure that incorporates metals in 2+ and 3+ oxidation states, thus significantly widening the possible combinations of metals to replace lead in PSCs.