Though generally considered insulating, recent progress on the discovery of conductive porous metal-organic frameworks (MOFs) offers new opportunities for their integration as electroactive components in electronic devices. Compared to classical semiconductors, these metal-organic hybrids combine the crystallinity of inorganic materials with easier chemical functionalization and processability. Still, future development depends on the ability to produce high-quality films with fine control over their orientation, crystallinity, homogeneity, and thickness. Here self-assembled monolayer substrate modification and bottom-up techniques are used to produce preferentially oriented, ultrathin, conductive films of Cu-CAT-1. The approach permits to fabricate and study the electrical response of MOF-based devices incorporating the thinnest MOF film reported thus far (10 nm thick).

We report on polariton condensation in photonic molecules formed by two coupled micropillars. We show that the condensation process is strongly affected by the interaction with the cloud of uncondensed excitons. Depending on the spatial position of these excitons within the molecule, condensation can be triggered on both binding and anti-binding polariton states of the molecule, on a metastable state or a total transfer of the condensate into one of the micropillars can be obtained. Our results highlight the crucial role played by relaxation kinetics in the condensation process.PACS numbers: 71.36.+c, 67.85.Hj, 78.67.Pt, 78.55.Cr Most of the experimental studies in atomic Bose condensates have explored conditions of thermodynamic equilibrium since typical condensate lifetimes are much longer than interaction times. Recent theoretical proposals have shown that out of equilibrium bosonic systems present qualitatively new behaviors [1]. One proposed way to reach this regime is the use of photonic systems with effective photon-photon interactions and dissipation provided by inherent optical losses [2]. Localized to delocalized phase transitions [3,4], highly entangled states [5], or fermionisation effects in a ring of coupled sites [6] are predicted in such systems.Microcavity polaritons are a model system for the investigation of the physics of driven-dissipative boson condensates [7][8][9][10][11][12][13]. They are the quasi-particules arising from the strong coupling between excitons confined in quantum wells and the optical mode of a microcavity. Because of their light-matter nature, polaritons present peculiar properties: they interact efficiently with their environment through their excitonic part [14,15] while their photonic part enables efficient coupling with the free space optical modes. Polariton condensates can be generated in zero dimensional micropillars [11] or in arrays of pillars with fully controlled coupling [16,17]. In this configuration, the non-equilibrium nature of polariton condensates should allow the realization of metastable collective states, such as the self-trapped states in a bosonic Josephson junction [18][19][20].In the present paper we investigate polariton condensation in photonic molecules obtained by coupling two micropillars. We demonstrate that polariton interactions strongly affect the way condensation occurs in such coupled system, not only modifying the wavefunction of the polariton condensate, but also the relaxation dynamics. This effect, specific to an out-of-equilibrium bosonic system, is illustrated by considering different positions of the non resonant excitation within the molecule. When the excitation spot is placed at the center of the molecule, polariton condensation is observed on both binding and anti-binding states. Interactions induce strong changes in the condensate wavefunction, the most important one being the change in its spatial anisotropy.When the excitation spot is positioned on one of the two coupled micropillars, condensation occurs in a very diffe...

Conductive metal–organic frameworks are opening new perspectives for the use of these porous materials for applications traditionally limited to more classical inorganic materials, such as their integration into electronic devices. This has enabled the development of chemiresistive sensors capable of transducing the presence of specific guests into an electrical response with good selectivity and sensitivity. By combining experimental data with computational modelling, a possible origin for the underlying mechanism of this phenomenon in ultrathin films (ca. 30 nm) of Cu‐CAT‐1 is described.

Prussian blue (PB) represents a simple, economical, and eco-friendly system as cathode material for sodium-ion batteries (SIBs). However, structural problems usually worsen its experimental performance thus motivating the search for alternative synthetic strategies and the formation of composites that compensate these deficiencies. Herein, a straightforward approach for the preparation of PB/MoS 2 -based nanocomposites is presented. MoS 2 provides a 2D active support for the homogeneous nucleation of porous PB nanocrystals, which feature superior surface areas than those obtained by other methodologies, giving rise to a compact PB shell covering the full flake. The nanocomposite exhibits an excellent performance as cathode for SIBs with discharge capacity values up to 177 mA h g −1 and a specific capacitance of 354 F g −1 . These values are even larger for the intercalation of K + ions (up to 215 mA h g −1 , reaching a specific capacitance of 489 F g −1 ). Compared to similar composites, superior performance can be ascribed to a synergistic effect of the coordination compound with the 2D material.

Abstract:In the race towards two-dimensional electronic and optoelectronic devices, semiconducting transition metal dichalcogenides (TMDCs) from group VIB have been intensively studied in recent years due to the indirect to direct band-gap transition from bulk to the monolayer. However, new materials still need to be explored. For example, semiconducting TMDCs from group IVB have been predicted to have larger mobilities than their counterparts from group VIB in the monolayer limit. In this work we report the mechanical exfoliation of ZrX 2 (X = S, Se) from bulk down to the monolayer and we study the dimensionality dependence of the Raman spectra in ambient conditions. We observe Raman signal from bulk to few layers and no shift in the peak positions is found when decreasing the dimensionality. While a Raman signal can be observed from bulk to a bilayer for ZrS 2 , we could only detect signal down to five layers for flakes of ZrSe 2 . These results show the possibility of obtaining atomically thin layers of ZrX 2 by mechanical exfoliation and represent one of the first steps towards the investigation of the properties of these materials, still unexplored in the two-dimensional limit.