Single‐crystalline ZnS nanobelts with sharp ultraviolet‐light emission (∼337 nm) at room temperature have been assembled as UV Sensors. The high spectral selectivity, combined with high photosensitivity and fast response time, justifies the effective utilization of the present ZnS nanobelts as “visible‐light‐blind” UV photodetectors in different areas.

The synthesis of high-quality In2Se3 nanowire arrays via thermal evaporation method and the photoconductive characteristics of In2Se3 individual nanowires are first investigated. The electrical characterization of a single In2Se3 nanowire verifies an intrinsic n-type semiconductor behavior. These single-crystalline In2Se3 nanowires are then assembled in visible-light sensors which demonstrate a fast, reversible, and stable response. The high photosensitivity and quick photoresponse are attributed to the superior single-crystal quality and large surface-to-volume ratio resulting in fewer recombination barriers in nanostructures. These excellent performances clearly demonstrate the possibility of using In2Se3 nanowires in next-generation sensors and detectors for commercial, military, and space applications.

Vertically aligned ZnO nanonails and nanopencils are synthesized on a silicon substrate using a modified thermal‐evaporation process, without using a catalyst or predeposited buffer layers. An adiabatic layer is used to provide an abrupt temperature decrease and high gas concentration for the nanostructures growth. The structure and morphology of the as‐synthesized ZnO nanonails and nanopencils are characterized using X‐ray diffraction, and scanning and transmission electron microscopies. Raman and photoluminescence properties are also investigated at room temperature. Field‐emission characterization shows that the turn‐on fields for the vertically aligned ZnO nanonails and nanopencils are 7.9 and 7.2 V μm–1, respectively.

Here, a facile and effective route toward full control of vertical ZnO nanorod (NR)/nanowire (NW) arrays in centimeter‐scale areas and considerable improvement of field‐emission (FE) performance is reported. Controlled deformation of colloidal crystal monolayer templates is introduced by heating near glass‐transition temperature. The NR/NW density, uniformity, and tapering were all adjusted through selection of template size and deformation, and electrolyte composition. In line with the adjustments, the field‐emission performance of the arrays is significantly improved. A low turn‐on electric field of 1.8 V µm−1, a field‐enhancement factor of up to 5 750, and an emitting current density of up to 2.5 mA cm−2 were obtained. These improved parameters would benefit their potential application in cold‐cathode‐based electronics.

Solvents were of the highest purity grade commercially available, and THF was freshly distilled over Na/benzophenone under a nitrogen atmosphere.Spectroscopic irradiations were performed using a low-output source (15 W) with emission centered at 300 nm in quartz cells 10 mm wide, equipped with a gas-tight rubber septum. Solutions (1.8 × 10-5 M) were equilibrated in air or thoroughly flushed by purging with argon for 15 min. Absorption spectra were recorded on a Varian 5000 UV-vis-near-IR spectrophotometer.Preparative irradiations were performed at room temperature, on 80 mL dichloromethane solutions of 1 (1.5 × 10 -3 M), using a highpressure Hg lamp (Helios Italquartz srl. 125 W) equipped with a glass cooling jacket, immersed in a borosilicate glass vessel under vigorous stirring. Nitrogen was gently purged for 30 min prior to the irradiation and the system was maintained under a nitrogen atmosphere during the reaction.Emission quantum yields were measured by means of a Varian Eclipse fluorimeter, for solutions with optical density ca. 0.1, using Cu II phtalocyanine in tetrahydrofuran as a reference standard. Corrections were performed for different refractive indexes of the solvents, for the optical density of the solutions, and for the different sensitivity of the photodetector.Cyclic voltammetry was performed in argon-flushed analyticalgrade dichloromethane solutions (4 × 10 -3 M), using a polished platinum working electrode, a platinum wire as the counter electrode and Ag/Ag + as the reference electrode. [(Bu) 4 N] + [PF 6 ] -was used as the supporting electrolyte and ferrocene was added as an internal reference. Scans were performed at 100 mV s