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The control of the crystal orientation and diameter of vertically grown epitaxial Si nanowires was demonstrated using a combination of a vapor–liquid–solid (VLS) growth technique and the use of an anodic aluminum oxide (AAO) template on a single-crystal Si substrate. The [100], [110], and [111] nanowires were selectively obtained by choosing the Si substrate with appropriate crystal orientation. The diameter of a Si nanowire in the AAO template could be controlled by the modification of the pore size of the AAO template with anodic voltage during anodization.

Copper-zinc-tin-sulfide (CZTS) solar cells have now become a topic of interest in the solar power generation industry. These are used as an absorber in the zinc oxide (ZnO)/cadmium sulfide (CdS) core-shell nanowire arrays, in order to improve the performance of solar cells. The relationship between the average increase in absorption rates and CdS shell thickness (compared to the thin film) reveals that the optimum thickness with the maximum average absorption rate (39.95%) compared to thin film is 30 nm. The cells’ electrical and optical performance was significantly improved with the introduction of graphene between the ZnO and CdS layers. The shell thicknesses for a better performance of these nanowire solar cells were 30 and 40 nm, with almost the same open-circuit voltage, the similar short-circuit current density, and efficiency, which were 630 mV, 6.39 mA/cm2, and 16.8%, respectively. Furthermore, a minimum reflection of 40% was obtained with these same shell thicknesses.

Lobster-eye optics is a promising option to establish an all-sky monitor in the X-ray spectrum. With the development of micromachining technology, the performance of lobster-eye optics is gradually improving and has become more practical. In this paper, from an optical design point of view, the mathematical models of the square-channel lobster-eye lens and the meridional lobster-eye lens have been established based on prism analysis, and the focusing property differences of the two lenses are analyzed. There are several key conclusions: the square-channel lobster lens has no paraxial ideal focal point; the meridional lobster eye lens has better energy concentration for focusing and a weaker capacity for energy collection than the square-channel lobster eye lens in the high-energy X-ray spectrum; and the stray light arms of the square lobster-eye lens appear earlier than those of the meridional lobster-eye lens when the photon energy decreases. These conclusions can help improve the design of a lobster-eye lens for space detection and exploration.

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