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NaV6O15 nanoplates are successfully prepared by a facile and low-cost self-combustion method, which can be considered as promising cathode materials for high capacity sodium-ion batteries (NIBs). Morphology analysis suggests that the self-combustion method leads to the NaV6O15 nanoplates possessing uniform size, with an average length of 400 nm and width of 100 nm. As the cathode materials, the NaV6O15 nanoplates exhibit a high initial discharge specific capacity of 149.48 mAh g-1 at a current density of 20 mA g-1 and remains 81.99 mAh g-1 after 30 cycles. The volume change is as little as 6.4%, which is demonstrated by the first-principles calculation. To understand the diffusion performance of sodium ion in NaV6O15 crystalline lattice, the diffusion coefficients of sodium ion are investigated by the electrochemical impedance spectroscopy (EIS) method and the first-principles calculation. The vacancy-hopping diffusion mechanism is proposed based on a quasi-2D energy favorable trajectory, which relieves the sodium ions diffuse along b-axis in NaV6O15 lattice with desirable activation energy of 0.481 eV. [ABSTRACT FROM AUTHOR]

Composition-controllable ternary CdSexS1-x quantum dots (QDs) with multiple emission colors were obtained via a hot-injection-like method at a relatively low injection temperature (230°C) in octadecene. Then highly fluorescent CdSexS1-x=ZnS core/shell (CS) QDs were synthesized by a facile single-molecular precursor approach. The fluorescent quantum yield of the resulting green (λem D 523 nm), yellow (λem D 565 nm) and red (λem D 621 nm) emission of CS QDs in toluene reached up to 85%, 55% and 39%, respectively. Moreover, a QDs white light-emitting diode (QDs-WLED) was fabricated by hybridizing green-, yellowand red-emitting CdSexS1-x=ZnS CS QDs/epoxy composites on a blue InGaN chip. The resulting four-band RYGB QDs-WLED showed good performance with CIE-1931 coordinates of (0.4137, 0.3955), an Ra of 81, and a Tc of 3360 K at 30 mA, which indicated the combination of multiple-color QDs with high fluorescence QYs in LEDs as a promising approach to obtain warm WLEDs with good color rendering. [ABSTRACT FROM AUTHOR]

Silicon based optoelectronic integration is restricted by its poor optoelectronic properties arising from the indirect band structure. Here, by combining silicon with another promising optoelectronic material, the CdS nanoribbon (NR), devices with heterojunction structure were constructed. The CdS NRs were also doped with gallium to improve their n-type conductivity. A host of nano-optoelectronic devices, including light emitting diodes, photovoltaic devices, and photodetectors, were successfully constructed on the basis of the CdS:Ga NR/Si heterojunctions. They all exhibited excellent device performances as regards high stability, high efficiency, and fast response speed. It is expected that the CdS NR/Si heterojunctions will have great potential for future applications of Si based optoelectronic integration. [ABSTRACT FROM AUTHOR]