日本物理学会誌及びJournal of the Physical Society of Japanの月刊について

Advanced energy conversion and storage (ECS) devices (including fuel cells, photoelectrochemical water splitting cells, solar cells, Li-ion batteries and supercapacitors) are expected to play a major role in the development of sustainable technologies that alleviate the energy and environmental challenges we are currently facing. The successful utilization of ECS devices depends critically on synthesizing new nanomaterials with merits of low cost, high efficiency, and outstanding properties. Recent progress has demonstrated that nanostructured metal chalcogenides (MCs) are very promising candidates for efficient ECS systems based on their unique physical and chemical properties, such as conductivity, mechanical and thermal stability and cyclability. In this review, we aim to provide a summary on the liquid-phase synthesis, modifications, and energy-related applications of nanostructured metal chalcogenide (MC) materials. The liquid-phase syntheses of various MC nanomaterials are primarily categorized with the preparation method (mainly 15 kinds of methods). To obtain optimized, enhanced or even new properties, the nanostructured MC materials can be modified by other functional nanomaterials such as carbon-based materials, noble metals, metal oxides, or MCs themselves. Thus, this review will then be focused on the recent strategies used to realize the modifications of MC nanomaterials. After that, the ECS applications of the MC/modified-MC nanomaterials have been systematically summarized based on a great number of successful cases. Moreover, remarks on the challenges and perspectives for future MC research are proposed (403 references).

Nanostructured metal chalcogenides: synthesis, modification, and applications in energy conversion and storage devices

A2B′B″O6 perovskites: A review

The quantum-confined Stark effect in single cadmium selenide (CdSe) nanocrystallite quantum dots was studied. The electric field dependence of the single-dot spectrum is characterized by a highly polarizable excited state (∼10 5 cubic angstroms, compared to typical molecular values of order 10 to 100 cubic angstroms), in the presence of randomly oriented local electric fields that change over time. These local fields result in spontaneous spectral diffusion and contribute to ensemble inhomogeneous broadening. Stark shifts of the lowest excited state more than two orders of magnitude larger than the linewidth were observed, suggesting the potential use of these dots in electro-optic modulation devices.

Quantum Confined Stark Effect in Single CdSe Nanocrystallite Quantum Dots

A novel crystal configuration of sandwiched S-Mo-Se structure (Janus SMoSe) at the monolayer limit has been synthesized and carefully characterized in this work. By controlled sulfurization of monolayer MoSe2 the top layer of selenium atoms are substituted by sulfur atoms while the bottom selenium layer remains intact. The peculiar structure of this new material is systematically investigated by Raman, photoluminescence and X-ray photoelectron spectroscopy and confirmed by transmission-electron microscopy and time-of-flight secondary ion mass spectrometry. Density-functional theory calculations are performed to better understand the Raman vibration modes and electronic structures of the Janus SMoSe monolayer, which are found to correlate well with corresponding experimental results. Finally, high basal plane hydrogen evolution reaction (HER) activity is discovered for the Janus monolayer and DFT calculation implies that the activity originates from the synergistic effect of the intrinsic defects and structural strain inherent in the Janus structure.

Janus Monolayer Transition Metal Dichalcogenides

Fe(3)Se(4) nanostructures have been synthesized by a one-pot high-temperature organic-solution-phase method. The size of these nanostructures can be tuned from 50 to 500 nm, and their shapes can be varied from nanosheets and nanocacti to nanoplatelets. These nanostructures exhibit hard magnetic properties, with giant coercivity values reaching 40 kOe at 10 K and 4 kOe at room temperature. The estimated magnetocrystalline anisotropy constant is 6 x 10(6) erg cm(-3), comparable to that of hexagonal close-packed cobalt. The magnetic properties can be further tuned by substituting Fe ions by other transition-metal elements such as Co.

Fe3Se4 Nanostructures with Giant Coercivity Synthesized by Solution Chemistry

The hard magnetic properties of Fe(3)Se(4) nanostructures were studied both experimentally and theoretically. Magnetic measurements showed that Fe(3)Se(4) nanoparticles can exhibit giant coercivity exceeding 40 kOe at low temperature (10K). This unusually large coercivity is attributed to the uniaxial magnetocrystalline anisotropy of the monoclinic structure of Fe(3)Se(4) with ordered cation vacancies. The measured anisotropy constant is 1.0 x 10(7) erg/cm(3), consistent with the result from first-principles calculations. The magnetization reversal mechanism of the nanoparticles is found to be incoherent spin rotation. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3662388]

Magnetic anisotropy and coercivity of Fe3Se4 nanostructures

A single source three-stage evaporation approach to CIGS absorber layer for thin film solar cells

Carrier-dopant exchange interactions in Mn-doped PbS colloidal quantum dots were studied by circularly polarized magneto-photoluminescence. Mn substitutional doping leads to paramagnetic behavior down to 5 K. While undoped quantum dots show negative circular polarization, Mn doping changes its sign to positive. A circular polarization value of 40% was achieved at T = 7 K and B = 7 tesla. The results are interpreted in terms of Zeeman splitting of the band edge states in the presence of carrier-dopant exchange interactions that are qualitatively different from the s,p-d exchange interactions in II-VI systems.

Carrier-dopant exchange interactions in Mn-doped PbS colloidal quantum dots

Carrier-dopant exchange interactions in Mn-doped PbS colloidal quantum dots were studied by circularly polarized magneto-photoluminescence. Mn substitutional doping leads to paramagnetic behavior down to 5 K. While undoped quantum dots show negative circular polarization, Mn doping changes its sign to positive. A circular polarization value of 40% was achieved at T=7 K and B=7 tesla. The results are interpreted in terms of Zeeman splitting of the band edge states in the presence of carrier-dopant exchange interactions that are qualitatively different from the s,p-d exchange interactions in II-VI systems.

Gen Long

Papers

Fe3Se4 Nanostructures with Giant Coercivity Synthesized by Solution Chemistry

Magnetic anisotropy and coercivity of Fe3Se4 nanostructures

A single source three-stage evaporation approach to CIGS absorber layer for thin film solar cells

Carrier-dopant exchange interactions in Mn-doped PbS colloidal quantum dots

Carrier-Dopant Exchange Interactions in Mn-doped PbS Colloidal Quantum Dots