Efficient visible-light photocatalytic activity by band alignment in mesoporous ternary polyoxometalate Ag2SCdS semiconductors
Porous multicomponent semiconductor materials show improved photocatalytic performance due to the large and accessible pore surface area and high charge separation efficiency. Here we report the synthesis of well-ordered porous polyoxometalate (POM) Ag2SCdS hybrid mesostructures featuring a controllable composition and high photocatalytic activity via a two-step hard-templating and topotactic ion-exchange chemical process. Ag2S compounds and […]
Coupled counterrotating polariton condensates in optically defined annular potentials
Polariton condensates are macroscopic quantum states formed by half-matter half-light quasiparticles, thus connecting the phenomena of atomic Bose Einstein condensation, superfluidity, and photon lasing. Here we report the spontaneous formation of such condensates in programmable potential landscapes generated by two concentric circles of light. The imposed geometry supports the emergence of annular states that extend […]
Optoelectronics: A practical polariton laser
Semiconductor lasers have become the backbone of modern optical telecommunications and are also used in an increasing number of applications in engineering, biology, chemistry and medicine. Historically, semiconductor laser device technology took off following the demonstration of electrical injection in double heterostructure diodes in the late 1960s. In these devices, confinement of electrically injected electron […]
Controlling the Thermomechanical Behavior of Nanoparticle/Polymer Films
We show that the mesoscale (~200 nm) thermomechanical properties of polymer nanocomposites formed from silica nanoparticles (NPs) and poly(2-vinylpyridine) (P2VP) critically depend on their interfacial structure, which can be controlled by the casting solvent. The results emphasize the important role of solvent in determining the interfacial structure of nanocomposites, which can be used to tailor […]
High Surface Area Ordered Mesoporous BiFeO3 Semiconductor with Efficient Water Oxidation Activity
Bismuth ferrite (BiFeO3) is important multiferroic oxide material because of the unique magnetic and ferroelectric properties. Here, we synthesize for the first time highly ordered mesoporous BiFeO3 semiconductor using tartaric acid-assisted growth of BiFeO3 compound inside the pores of carbon template. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 physisorption measurements reveal that […]
Relaxation Oscillations in the Formation of a Polariton Condensate
We report observation of oscillations in the dynamics of a microcavity polariton condensate formed under pulsed nonresonant excitation. While oscillations in a condensate have always been attributed to Josephson mechanisms due to a chemical potential unbalance, here we show that under some localization conditions of the condensate, they may arise from relaxation oscillations, a pervasive […]
Highly Efficient Flexible Hybrid Nanocrystal-Cu(In,Ga)Se2 (CIGS) Solar Cells
A novel scheme for hybridizing inkjet-printed thin film Cu(In,Ga)Se2 (CIGS) solar cells with self-assembled clusters of nanocrystal quantum dots (NQDs), which provides a 10.9% relative enhancement of the photon conversion efficiency (PCE), is demonstrated. A non-uniform layer of NQD aggregates is deposited between the transparent conductive oxide and a CdS/CIGS p-n junction using low cost […]
Template-Directed Assembly of Metal-Chalcogenide Nanocrystals into Ordered Mesoporous Networks
Although great progress in the synthesis of porous networks of metal and metal oxide nanoparticles with highly accessible pore surface and ordered mesoscale pores has been achieved, synthesis of assembled 3D mesostructures of metal-chalcogenide nanocrystals is still challenging. In this work we demonstrate that ordered mesoporous networks, which comprise well-defined interconnected metal sulfide nanocrystals, can […]
Ion-Exchangeable Molybdenum Sulfide Porous Chalcogel: Gas Adsorption and Capture of Iodine and Mercury
We report the synthesis of ion-exchangeable molybdenum sulfide chalcogel through an oxidative coupling process, using (NH4)2MoS4 and iodine. After supercritical drying, the MoSx amorphous aerogel shows a large surface area up to 370 m2/g with a broad range of pore sizes. X-ray photoelectron spectroscopic and pair distribution function analyses reveal that Mo6+ species undergo reduction […]
A new class of tunable hypersonic phononic crystals based on polymer-tethered colloids
Hybridization-type band gaps are known to persist, despite structural disorder, in phononic crystals; however their fabrication remains challenging for all-solid hypersonic composites. Here, the authors utilize the elastic anisotropy at the interface of polymer-tethered colloidal particles to control phonon propagation in GHz regime. From: E. Alonso-Redondo, M. Schmitt, Z. Urbach, C. M. Hui, R. Sainidou, […]