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Low Turn-on Field (low + turn-on_field)
Selected AbstractsField Emission and Cathodoluminescence of ZnS Hexagonal Pyramids of Zinc Blende Structured Single CrystalsADVANCED FUNCTIONAL MATERIALS, Issue 3 2009Zhi-Gang Chen Abstract Single-crystal hexagonal pyramids of zinc blende ZnS are fabricated by facile thermal evaporation in an ammonia atmosphere at 1150,°C. It is found that ZnS pyramids grow along the [111] crystal axis and possess a sharp tip with a diameter of ,10,nm and a micrometer-sized base. The structural model and growth mechanism are proposed based on crystallographic characteristics. This unique ZnS pyramid structure exhibits a low turn-on field (2.81,V µm,1), a high field-enhancement factor (over 3000), a large field-emission current density (20,mA cm,2), and good stability with very small fluctuation (0.9%). These superior field-emission properties are clearly attributed to the pyramid morphology, with micrometer-sized bases and nanotips, and high crystallinity. Moreover, a stable UV emission of 337,nm at room temperature is observed and can be ascribed to the band emission of the zinc blende phase. These results suggest that the ZnS hexagonal pyramids can be expected to find promising applications as field emitters and optoelectronic devices. [source] ZnS Branched Architectures as Optoelectronic Devices and Field EmittersADVANCED MATERIALS, Issue 21 2010Zhi-Gang Chen A unique ZnS branched architecture was fabricated by a facile thermal evaporation method. Stable UV emission at 327,nm and superior field emission with a low turn-on field, a high field-enhancement factor, a large current density, and small fluctuation were observed. [source] Ultrafine ZnS Nanobelts as Field Emitters,ADVANCED MATERIALS, Issue 18 2007S. Fang Single-crystalline, narrow-size- distribution ultrafine ZnS nanobelts (see figure), revealing a notable quantum-confinement effect, have been synthesized at a high yield by controlling the evaporation and agglomeration rates. Field-emission measurements show ultrafine ZnS nanobelts are very good field emitters with a low turn-on field and high field-enhancement factor. [source] The Growth of One-Dimensional Single-Crystalline AlN Nanostructures by HVPE and Their Field Emission Properties,CHEMICAL VAPOR DEPOSITION, Issue 1-3 2010Yun-Ki Byeun Abstract Single-crystalline AlN nanostructures, such as thin films, nanoneedles, nanocolumns, and nanowires, depending on the controlled gas-flow ratio, are synthesized by halide vapor-phase epitaxy (HVPE). In comparison with a typical vapor/liquid/solid (VLS) mechanism for the growth of nanowires, well-aligned AlN nanorod arrays with diameters below 20,nm are grown on a catalyst-free Si substrate though a vapor/solid (VS) mechanism. Their structural and optical properties are measured by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL). In particular, AlN nanorods exhibit an excellent field emission property with a low turn-on field of 2.25,V,µm,1. The field enhancement factor is estimated to be about 784 due to well-aligned, needle-shaped, AlN nanorods. [source] | ||||||||||