Controlled low-temperature fabrication of ZnO nanopillars with a wet-chemical approach

Abstract

Aqueous chemical growth (ACG) is an efficient way to generate wafer-scale and densely packed arrays of ZnO nanopillars on various substrate materials. ACG is a low-temperature growth approach that is only weakly influenced by the substrate and even allows growth on flexible polymer substrates or on conducting materials. The advanced fabrication of wafer-scale and highly vertically aligned arrays of ZnO nanopillars on various substrate materials is demonstrated. Moreover, it is possible to control the morphology in diameter and length by changing the growth conditions. Photoluminescence characterization clearly shows a comparatively strong band-edge luminescence, even at room temperature, that is accompanied by a rather weak visible luminescence in the yellow/orange spectral range.

One-dimensional ZnO nanostructures: Solution growth and functional properties

“…Experiments have shown that due to depletion of Zn 2+ ions the growth of the ZnO nanowires normally slowed down with time and eventually arrived at growth-dissolution equilibrium for longer reaction times. This limitation can be overcome by adding additional Zn nitrate solution [79], or by replenishing the growth solution [77,78,80]. Under the mediation of NH 3 ·H 2 O, however, Zn 2+ could be stabilized through the reversible reaction shown in equation (8) below, thus, leading to a relatively low level of supersaturation being maintained in the solution.…”

Thermo-electrochemical selective growth of ZnO nanorods on any noble metal electrodes

“…It has been reported that both the length and diameter of the ZnO nanorods increased with the reaction time in the hydrothermal growth method [14,15]. It was noticed from the SEM images that in 0.025 M zinc nitrate hydrate growth solution, the 6 h grown ZnO nanorods were distributed uniformly with an average diameter of about 170 nm and an average length of about 2 µm.…”

Chemically Modified Metal Oxide Nanostructures Electrodes for Sensing and Energy Conversion

“…During growth the expected pH value might be between 6.5 and 7. 111 The produced Zn(OH)2 is thermodynamically unstable and it would be dehydrated when it is incorporated into the crystal, therefore could be referred as a growth unit. 55 Before the substrates were placed into the solution, and to prepare contact pads for the electrochemical measurements, a small part of the Au coated glass was covered.…”