Controlled Growth of Supported ZnO Inverted Nanopyramids with Downward Pointing Tips

Abstract

High purity porous ZnO nanopyramids with controllable properties are grown on their tips on Si(100) substrates by means of a catalyst-free vapor phase deposition route in a wet oxygen reaction environment. The system degree of preferential [001] orientation, as well as nanopyramid size, geometrical shape and density distribution, can be finely tuned by varying the growth temperature between 300 and 400°C, whereas higher temperatures lead to more compact systems with a three-dimensional (3D) morphology. A growth mechanism of the obtained ZnO nanostructures based on a self-catalytic vapor-solid (VS) mode is proposed, in order to explain the evolution of nanostructure morphologies as a function of the adopted process conditions. The results obtained by a thorough chemico-physical characterization enable to get an improved control over the properties of ZnO nanopyramids grown by this technique. Taken together, they are of noticeable importance not only for fundamental research on ZnO nanomaterials with controlled nano-organization, but also to tailor ZnO functionalities in view of various potential applications.

Zinc Oxide Grown by Atomic Layer Deposition: From Heavily n‐Type to p‐Type Material

“…Among these are sensors, surface acoustic wave devices, transparent electrodes for solar cells, transparent electronics, ultraviolet light emitters, and others. An additional advantage of this material, important for applications, is feasibility to grow a wide range of nanostructures, thin films, and single crystals . The latter ones provide good quality single‐crystal substrates for a homoepitaxy .…”

“…Zinc oxide films can be obtained by many growth techniques such as pulsed laser deposition (PLD), radio‐frequency magnetron sputtering, chemical vapor deposition (CVD), or molecular beam epitaxy (MBE) . Atomic layer deposition (ALD) has several advantages over other growth methods, among which are a precise control of thickness at the nanometer scale, a possibility to perform deposition on large substrates, or an opportunity to obtain thin ZnO films at temperatures low enough for deposition on organic substrates or in the back end Of line (BEOL) technology .…”

Dual Functions of CO2 Molecular Activation and 4f Levels as Electron Transport Bridge in Dysprosium Single Atom Composite Photocatalysts with Enhanced Visible‐Light Photoactivities

“…Therefore, the use of photocatalysts to achieve an efficient conversion of CO 2 into green energy under the irradiation of clean solar energy is a popular choice of effective means. [16][17][18][19][20][21][22][23][24][25][26] It is well known that the construction of excellent photocatalytic materials is a necessary means to improve photocatalytic performance. [27][28][29][30][31] Among the photocatalytic materials reported, the bandgap of graphite carbon nitride (g-C 3 N 4 ) is ≈2.7 eV, and the conduction band (CB) level is relatively negative, which promotes the reduction capability of photogenerated electrons.…”

A univariate ternary logic and three-valued multiplier implemented in a nano-columnar crystalline zinc oxide memristor

“…[23][24][25] Regarding these concerns, zinc oxide (ZnO) is considered to be a promising candidate for memristors due to its simple stoichiometry, facile fabrication, and good compatibility with the CMOS platform, as well as its tunable resistive switching characteristics via doping and microstructure manipulation. [26][27][28][29][30][31][32] In particular, its columnar crystalline structure with vertical grain boundaries along the direction of growth may provide a cut-through pathway for oxygen anion or oxygen vacancy migration [33][34][35][36] and facilitate the formation of pseudo-straight conductive laments across the switching layer ( Fig. 1a-c).…”