Diameter optimization of VLS-synthesized ZnO nanowires, using statistical design of experiment

Abstract

The possibility of diameter optimization of ZnO nanowires by using statistical design of experiment (DoE) is investigated. In this study, nanowires were synthesized using a vapor–liquid–solid (VLS) growth method in a horizontal reactor. The effects of six synthesis parameters (synthesis time, synthesis temperature, thickness of gold layer, distance between ZnO holder and substrate, mass of ZnO and Ar flow rate) on the average diameter of a ZnO nanowire were examined using the fractional factorial design (FFD) coupled with response surface methodology (RSM). Using a 2III6−3 FFD, the main effects of the thickness of the gold layer, synthesis temperature and synthesis time were concluded to be the key factors influencing the diameter. Then Box–Behnken design (BBD) was exploited to create a response surface from the main factors. The total number of required runs for the DoE process is 25, 8 runs for FFD parameter screening and 17 runs for the response surface obtained by BBD. Three extra runs are done to confirm the predicted results.

A Zinc Oxide Nanowire Pressure Sensor

“…These values include the distance from powder to substrate, which was 210 mm, and the amount of powder, which was 2 g ZnO and 2 g graphite. These were the only two critical values that were not varied [108].…”

“…These values were chosen through a combination of trial and error in previous experiments, and also from articles on the growth of zinc oxide nanowires [108]. External effects that influence the growth included factors that were not under the experimenter's direct control, and some that were under the experimenter's control, but did not receive any attention.…”

“…For an experiment of this kind, with more than two input factors and a very precise output factor, factorial design works the best [109,108]. A complete description and explanation of factorial design is beyond the scope of this thesis, but a brief introduction and an explanation of the most important formulas will be given.…”

Effect of pH variations and characterization of short length ZnO hexagonal nanorods from ZnS precursors

“…vapor-liquid-solid (VLS) [14,15], metal organic Vapor -phase epitaxy (MOVPE) [16], pulsed laser deposition (PLD) [17,18] solution, and hydrothermal methods [19,20].…”

Influence of solvents on the hydrothermal formation of one‐dimensional magnesium hydroxide

“…), the soft template method (polymers [8], etc. ), the chemical vapor deposition [9,10], the arc discharge [11] and the laser ablation [12], etc. In recent years the solvothermal and hydrothermal methods have been used as alterative ways for the synthesis of 1D nanomaterials owing to the moderate condition, the easy control of the process and the perfect properties of the products.…”