In this work, graphene layers on SiO 2 /Si substrate have been chemically decorated by radio frequency hydrogen plasma. Hydrogen coverage investigation by Raman spectroscopy and micro-X-ray photoelectron spectroscopy characterization demonstrates that the hydrogenation of single layer graphene on SiO 2 /Si substrate is much less feasible than that of bilayer and multilayer graphene. Both the hydrogenation and dehydrogenation process of the graphene layers are controlled by the corresponding energy barriers, which show significant dependence on the number of layers. The extent of decorated carbon atoms in graphene layers can be manipulated reversibly up to the saturation coverage, which facilitates engineering of chemically decorated graphene with various functional groups via plasma techniques.

The thermally induced softening of the elastic and vibronic identities in crystals and their correlations have long been a puzzle. Analytical solutions have been developed, showing that the detectable elastic and vibronic properties could be related directly to the bonding parameters, such as bond length and strength, and their response to the temperature change. Reproduction of measured T-dependent Young's modulus and Raman shift of Si, Ge, and diamond reveals that the thermally driven softening of the elasticity and the optical Raman frequency arises from bond expansion and vibration, with derived information about the atomic cohesive energy and clarification of their interdependence.

GaAsN was grown by molecular beam epitaxy equipped with a radio frequency nitrogen plasma source. The N incorporation behaviors were investigated using a series of samples grown at different growth rates, As4/Ga ratios, and nitrogen fluxes within a growth temperature range from 420 to 560 °C. It was found that, for the GaAsN grown at higher growth rates (0.4–1.3 ML/s), the N concentration increased linearly following a decrease in growth rate, and kept independent of the arsenic pressure. For the GaAsN grown at lower growth rate (0.1–0.3 ML/s), the N concentration was significantly influenced by the arsenic pressure, and the increase in N concentration with decreasing growth rate follows a sublinear manner. We propose a model based on the incorporation competition of group V elements (N and As) under N underpressure and overpressure conditions, which can explain the different behaviors well.

The synthesis of vertically aligned single-walled carbon nanotubes (VA-SWNTs) by plasma-enhanced chemical vapor deposition (PECVD) was achieved at 500-600 °C, using ethylene as the carbon source and 1 nm Fe film as the catalyst. For growth of high-quality VA-SWNTs in a plasma sheath, it is crucial to alleviate the undesirable ion bombardment etching effects by the optimization of plasma input power and gas pressure. The resistibility of synthesized VA-SWNTs against ion bombardment etching was found to be closely related to the growth temperature. At relatively low temperature (500 °C), the VA-SWNTs were very susceptible to ion bombardments, which could induce structural defects, and even resulted in a structural transition to few-walled nanotubes. For capacitively coupled radio frequency (rf) PECVD operating at moderate gas pressure (0.3-10 Torr), the ion bombardment etching effect is mainly dependent on the ion flux, which is related to the plasma input power and gas pressure.