Narrow Results

Carbon nanotips were grown on a silicon substrate by negative bias-enhanced hot filament chemical vapor deposition without catalyst, using a mixture of methane, ammonia and hydrogen as the reaction gases. It was evidenced that the plasma caused by the bias played a key role in the formation of the carbon nanotips. Due to occurrence of plasma during growing carbon nanotips, the gases were ionized into various ions. Based on different effects of the ions, a growth mechanism of the carbon nanotips was put forward.

Magnetron sputtering has been the most widely useful technique having high deposition rates, uniformity over large areas of the substrates and easy control over the composition of the deposited films. The films properties depend on various deposition process parameters such as substrate temperature, sputtering power, oxygen partial pressure, sputtering pressure and post deposition conditions. Using reactive radio-frequency magnetron sputtering method, NiO thin films were prepared on glass substrates. The influence of negative bias on the crystal structure, surface morphological, optical property was investigated using X-ray diffraction, scanning electron microscopy and ultraviolet-visible spectrophotometer and Hall Effect tester, respectively. It is found that the negative bias can improve the crystallinity, flatness and photoelectric properties of the NiO films in a certain range. An optimal transmittance of 78% and resistivity of 0.6 Ω·cm is obtained when the negative bias is 100 V. This indicates that the negative bias is an important means to control the properties of the films.