Quintuple-shelled SnO2 hollow microspheres are prepared by a hard-template method. DSSCs constructed with SnO2 multi-shell photoanodes show a record photoconversion efficiency of 7.18% due to enhanced light scattering. SnO2 hollow microspheres that are utilized as a scattering layer on top of P25 films increase the DSSC photoconversion efficiency from 7.29% to 9.53%.

Symmetric n- and p-type field-effect transistors (FETs) have been fabricated on the same undoped single-walled carbon nanotube (SWCNT). The polarity of the FET is defined by controlled injection of electrons (n-type, via Sc electrodes) or holes (p-type, via Pd electrodes) into the SWCNT, instead of via chemically doping the SWCNT. The SWCNT-based FETs with different channel lengths show a clear trend of performance improvement for channel length scaling. Taking full advantage of the perfect symmetric band structure of the semiconductor SWCNT, a perfect SWCNT-based CMOS inverter is demonstrated, which gives a voltage gain of over 160, and for the two adjacent n- and p-type FETs fabricated on the same SWCNT, high field mobility is realized simultaneously for electrons (3000 cm(2)/V.s) and holes (3300 cm(2)/V.s).

In this study, we report a facile and rapid synthesis strategy for preparing ultralong ZnO nanowire (NW) arrays by anodizing zinc foil at room temperature in a slightly basic solution, followed by annealing treatment. Detailed structure and composition characterizations are presented, including scanning electron microscopy, energy-dispersive X-ray spectrometry, transmission electron microscopy, and X-ray diffraction. We also explore the effects of temperature, applied voltage, and pretreatment on the anodization process. On the optimized conditions, dense NW film can be achieved, resulting in the enhanced optical absorption. More importantly, the as-prepared ZnO NWs have exhibited reasonable electronic properties. The zinc anodization technique, which does not involve complex chemicals and steps, is a low-cost and high-efficiency approach to large-scale synthesis of ultralong ZnO NW film, suggesting the great potential in dye-sensitized solar cells and gas sensors.

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