Characterization of carbon nanotubes by chemical vapor deposition

Abstract

This study investigates novel multiwalled carbon nanotubes (MWCNTs) grown on agricultural waste, using loaded iron nanoparticles as catalyst templates and acetylene as carbon source through chemical vapor deposition under specific conditions, to wit: 550 °C reaction temperature, 47 min reaction time, and 1 gas ratio. The specifications of MWCNTs are analyzed and characterized with the use of field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results reveal that MWCNTs have high quality and unique morphologies.

Fabrication of GaN-based LEDs

“…Details of the growth procedures can be found elsewhere [13][14][15]. The LED structure consists of a 50-nm-thick GaN nucleation layer grown at 550 1C, a 3mm-thick Si-doped n-GaN buffer layer grown at 1050 1C, an undoped InGaN/GaN multiquantum well (MQW) active region grown at 770 1C, a 50-nm-thick Mg-doped p-Al 0.15 Ga 0.85 N electron blocking layer grown at 1050 1C, a 0.6-mm-thick Mg-doped p-GaN layer grown at 1050 1C and a Si-doped n þ short-period-superlattice (SPS) tunnel contact structure [16][17][18]. The InGaN/GaN MQW active region consists of five pairs of 3-nm-thick In 0.23 Ga 0.77 N well layers and 7-nm-thick GaN barrier layers.…”

Charge transfer in copper oxide nanostructure

“…Over the previous few years, several attempts have been made to improve the precipitation of copper (I) oxide thin films with various features such as shape, size, and architecture through electro-chemical deposition (ECD), which has generated a lot of interest. Because remarkable features may be attained, Cu2O can be adjusted into cubes [7], truncated, octahedral, faceted, polyhedral and flowerlike. By concentrating on the production of Cu2O films via electrodeposition approach, researchers started to regulate the shape of formed thin films based on the applied voltage, ingredients, temperatures and pH, concentrations and electrolytes.…”