Shu-Huei Hsieh

Adsorption behavior of heavy metal ions by carbon nanotubes grown on microsized Al2O3 particles

Carbon nanotubes (CNTs) were grown on the surface of microsized Al2O3 particles in CH4 atmosphere at 700°C under the catalysis of Fe-Ni nanoparticles. The CNTs on Al2O3 were used for adsorbing Pb2+, Cu2+, and Cd2+ from the solution and the results were compared with active carbon powders, commercial carbon nanotubes, and Al2O3 particles. The as-grown CNTs/Al2O3 have demonstrated extraordinary absorption capacity with further treatment or oxidation, as well as hydrophilic ability that other CNTs lacked. The adsorption capacity of CNTs on Al2O3 is superior to other adsorbents and the preference order of adsorption on composite Al2O3 is Pb2->Cu2+>Cd2+. It seemed that the adsorption of those Pb2+, Cu2+, and Cd2+ did not change the surface properties of composite particles. The adsorption behaviors of Pb2+, Cu2+, and Cd2+ by CNTs on Al2O3 match well with the Langmuir isothermal adsorption model and the second order kinetic model. The calculated saturation amount adsorbed by 1 g of CNTs on Al2O3 are 67.11, 26.59, and 8.89 mg/g for Pb2-, Cu2+, and Cd2+ in single adsorption test, respectively.

Effect of Fe metal on the growth of silicon oxide nanowires

Silicon oxide (SiO(subscript x)) nanowires are generally grown on Si substrate under the catalysis of Au in N2 atmosphere at elevated temperatures. Because the price of Au metal is quite high, Fe metal is then used to replace a part of Au for catalyzing the growth of SiO(subscript x) nanowires. The results show that the Fe film can be used as the diffusion barrier of Au. SiO(subscript x) nanowires are grown on Au/Fe/Si substrate at 1030℃. Under the catalysis of Fe/Au, the efficiency for the growth of SiO(subscript x) nanowires is promoted.

Synthesis of the CuInSe2 thin film for solar cells using the electrodeposition technique and Taguchi method

Abstract The Taguchi method was used to obtain the optimum electrodeposition parameters for the synthesis of the CuInSe 2 thin film for solar cells. The parameters consist of annealing temperature, current density, CuCl 2 concentration, FeCl 3 concentration, H 2 SeO 3 concentration, TEA amount, pH value, and deposition time. The experiments were carried out according to an L 18 (2 1 3 7 ) table. An X-ray diffractometer (XRD) and a scanning electron microscope (SEM) were respectively used to analyze the phases and observe the microstructure and the grain size of the CuInSe 2 film before and after annealing treatment. The results showed that the CuInSe 2 phase was deposited with a preferred plane (112) parallel to the substrate surface. The optimum parameters are as follows: current density, 7 mA/cm 2 ; CuCl 2 concentration, 10 mM; FeCl 3 concentration, 50 mM; H 2 SeO 3 concentration, 15 mM; TEA amount, 0 mL; pH value, 1.65; deposition time, 10 min; and annealing temperature, 500°C.

Kinetics of electroless Ni-Cu-P deposits on silicon in a basic hypophosphite-type bath

Abstract Electroless Ni-Cu-P deposits were deposited on the Si substrate in a basic hypophosphite-type plating bath. The effects of pH value and the metal source composition, Ni and Cu, in the plating bath on the kinetics of the Ni-Cu-P deposition were studied. The electroless Ni-Cu-P deposits were characterized by a scanning electron microscope, a transmission electron microscope, an energy dispersive X-ray spectroscope, and an X-ray diffractometer. The results showed that the pH value of the plating bath had no obvious effect on the morphology and composition of electroless Ni-Cu-P deposits. However, the composition of the metal source, Ni and Cu, in the plating bath had great effect on the kinetics of electroless Ni-Cu-P deposition.

Growth behavior of electroless copper on silicon substrate

Abstract The growth behavior containing deposit morphology, growth rate, activation energy, and growth mechanism of copper on silicon substrate, especially at the initial stage, in the electroless plating process was studied. Copper was deposited on the surface of the silicon substrate in an electroless plating bath containing formalin (CH2O 37vol%) as a reducing agent at a pH value of 12.5 and a temperature of 50-75°C. The copper deposit was characterized using a field emission scanning electron microscope and transmission electron microscope. The results showed that after the activation process, nanoscale Pd particles were distributed evenly on the surface of the silicon; in the deposition process, copper first nucleated at locations not only near the Pd particles but also between the Pd particles: the growth rate of electroless Cu ranged from 0.517 nm/s at 50°C to 1.929 nm/s at 75°C. The activation energy of electroless Cu on Si was 52.97 kJ/mol.

Interface Structure between Epitaxial NiSi2 and Si

The interface structure between the Si and NiSi2 epitaxially grown on the ((average)1 12) Si substrate was studied using high resolution transmission electron microscopy and computer image simulation. The results showed that the interface between Si and NiSi2 epitaxially grown on the ((average)1 12) Si substrate has six different types: Type A NiSi2 ((average)1 1 1)/((average)1 1 1) Si, type A NiSi2 (001)/(001) Si, type B NiSi2 (1 (average)1 (average)1)/(1 (average)1 1) Si, type B NiSi2 ((average)1 12)/(1 (average)1 2) Si, type B NiSi2 (2 (average)2 1)/(001) Si, and type B NiSi2 (1 (average)1(average)4)1 (1 (average)1 0) Si. And there are one or more different atomic structures for one type of interface.