Jean‐Jacques Delaunay

Abstract An increasing number of applications using ultraviolet radiation have renewed interest in ultraviolet photodetector research. Particularly, solar‐blind photodetectors sensitive to only deep UV (<280 nm), have attracted growing attention because of their wide applicability. Among recent advances in UV detection, nanowire (NW)‐based photodetectors seem promising, however, none of the reported devices possesses the required attributes for practical solar‐blind photodetection, namely, an

In this review, we discuss the merits and major challenges of p-type binary and ternary Cu-based metal oxide photocathodes and present the latest research effort in modifying the materials towards high-performance photocathodes.

The improved energy band alignment of Pt/TiO₂/Ga₂O₃/Cu₂O structure results in a positive onset potential of ∼1 V<italic>vs.</italic>RHE and a stable cathodic photocurrent under appropriate TiO₂deposition temperature.

For the utilization of renewable energy resources to become widespread, efficient energy-storage devices must be developed. Electrocatalysts for the oxygen evolution reaction (OER) are needed for a wide variety of such devices, including fuel cells, metal–air batteries, and photoelectrochemical cells. Here we demonstrate a defect-rich NiCeOx layer, directly synthesized on a Ni substrate through a simple two-step dip-coating/annealing process, as a highly active and stable OER catalyst made from

Cobalt–platinum–carbon thin film was deposited with a chemical composition of Co50Pt15C35. The film had a nanogranular morphology with a grain size ranging from 5 to 15 nm. It consisted of cobalt–platinum grains which had a faulted hexagonal close-packed phase and were separated by graphitelike carbon boundaries. The film in-plane coercivity was 1500 Oe, compared to a few hundreds oersteds in the case of cobalt–carbon. This result establishes a way of fabricating high coercivity cobalt–carbon ba

A hybrid structure that supports the coupling of a cavity mode and a Tamm plasmon (TP) mode is demonstrated as a spectrally selective thermal emitter for the mid-infrared spectral range. Unlike conventional TP structures, the presented hybrid structure contains an optical cavity sandwiched between the distributed Bragg reflector (DBR) and the metallic mirror of a typical TP structure. In simulation, the TP-cavity hybrid structure exhibits a strong peak (absorptance = 0.993) in the absorption spe

A dense array of vertically aligned ZnO-ZnGa(2)O(4) core-shell nanowires was synthesized on a large scale on an a-plane sapphire substrate by a simple two-step chemical vapor deposition method. The ZnO cores and ZnGa(2)O(4) shells of the nanowires are of single crystal quality and have aligned crystallographic orientations as evidenced from XRD and TEM analyses. Mott-Schottky analysis and voltage onset from the photocurrent-voltage curve confirm an n-type semiconductor property, a flat-band pote

We report highly stable and efficient sunlight water splitting on a ZnO–ZnGaON nanowire-array-on-a-film photoanode without the assistance of any co-catalyst. The single crystalline ZnO–ZnGaON nanowire-array-on-a-film photoanode was synthesized via a high-temperature vapor-phase diffusion reaction of gallium (Ga) and nitrogen (N) on a single crystal domain ZnO nanowire-array-on-a-film structure. The synthesized ZnO–ZnGaON photoanode offers visible light absorption through N incorporation, improve

Spectral selective thermal emitters are promising technological components due to their efficiency, large range of available emission wavelengths, simplicity, and long lifetime. Despite intensive effort into narrowband thermal emitters using surface plasmon polaritons, surface phonon polaritons, and Tamm plasmons, material losses have limited the potential quality factors, with the highest reported value being 200. Here, by combining a metallic mirror and an optical Tamm state structure, we prop

Cobalt–carbon thin films were deposited with a carbon concentration ranging from 27 to 57 at.% at different substrate temperatures. The morphology and phases of as-deposited films were investigated by transmission electron microscopy and x-ray diffraction. The effect of annealing on the microstructure is reported. Under particular conditions of substrate temperature, carbon concentration, and subsequent annealing, a granular morphology consisting of nanocrystalline cobalt grains embedded in grap

Tamm plasmonic (TP) structures, consisting of a metallic film and a distributed Bragg reflector (DBR), can exhibit pronounced light confinement allowing for enhanced absorption in the metallic film at the wavelength of the TP resonance. This wavelength dependent absorption can be converted into an electrical signal through the internal photoemission of energetic hot-electrons from the metallic film. Here, by replacing the metallic film at the top of a TP structure with a hot-electron device in a

Increased beneficial oxygen vacancies density is yielded in WO₃ photoanodes by calcination of WO₃·2H₂O rather than WO₃·H₂O.

Abstract In order to improve the performance of gas sensors based on ZnO nanoparticles, platinum was deposited on the nanoparticle surface using sputtering. Gas‐sensing experiments on Pt‐functionalized ZnO nanoparticles exhibited larger response to ethanol gas at lower operating temperature, attributed to the sensitization and spillover effects. The faster recovery time of Pt‐decorated ZnO nanoparticles is associated with the catalyst effect of Pt. The maximum sensitivity of Pt‐decorated ZnO nan