Graphene and carbon nanotubes (CNTs) are fascinating materials, both scientifically and technologically, due to their exceptional properties and potential use in applications ranging from high-frequency electronics to energy storage devices. This manuscript introduces a hybrid structure consisting of graphitic foliates grown along the length of aligned multiwalled CNTs. The foliate density and layer thickness vary as a function of deposition conditions, and a model is proposed for their nucleation and growth. The hybrid structures were studied using electron microscopy and Raman spectroscopy. The foliates consist of edges that approach the dimensions of graphene and provide enhanced charge storage capacity. Electrochemical impedance spectroscopy indicated that the weight-specific capacitance for the graphenated CNTs was 5.4× that of similar CNTs without the graphitic foliates. Pulsed charge injection measurements demonstrated a 7.3× increase in capacitance per unit area. These data suggest that this unique structure integrates the high surface charge density of the graphene edges with the high longitudinal conductivity of the CNTs and may have significant impact in charge storage and related applications.

The effect of direct current (dc) substrate bias on the promotion of nanocrystallization in Si network has been studied, specifically within He-diluted SiH4 plasma in radio frequency (RF)-plasma-enhanced chemical vapor deposition. In view of organizing nanocrystallinity, controlled transmission of energy to the growing surface is needed and that is obtainable from metastable helium (He*) bombardment and, in particular, ionic helium (He+) bombardment under negative substrate bias. The structural morphology has been adequately regulated to a homogeneous network restraining from an exclusive columnar structure that is coherent to low-temperature growth. Notable improvements in the film quality in terms of enhanced crystallinity with low hydrogen content as well as reduced incubation volume, bulk void, and surface roughness have been demonstrated, even at low substrate temperature and low RF power. Use of appropriate dc substrate-bias has been identified as a supplementary parameter efficiently organizing the growth, making it more device-friendly.

This article lays the foundation for the development of microwave plasma chemical vapor deposition process conditions for synthesizing multilayered microcrystalline and nanocrystalline diamond (MCD and NCD) thin films. The effects of gas composition and the diamond seeding medium are correlated with the film morphology and diamond phase purity. Results of process optimization experiments using single-layer diamond deposition indicate that for high gas-phase Ar content (≥90%) the film quality improves with reduced Ar content and with increasing thickness reaching a plateau above a thickness of ∼2 μm. Multilayer diamond deposition experiments with two different seeding media (25 nm and 1 μm) clearly show that it is feasible to selectively synthesize alternating MCD (60% Ar) and NCD (95% Ar) layers with good control of film quality and morphology, thereby setting the stage for development of multilayered diamond thin films with tailored properties for thermal management applications.

Organic plasma polymers are currently attracting significant interest for their potential in the areas of flexible optoelectronics and biotechnology. Thin films of plasma-polymerized polyterpenol fabricated under varied deposition conditions were studied using nanoindentation and nanoscratch analyses. Coatings fabricated at higher deposition power were characterized by improved hardness, from 0.33 GPa for 10 W to 0.51 GPa for 100 W at 500-μN load, and enhanced wear resistance. The elastic recovery was estimated to be between 0.1 and 0.14. Coatings deposited at higher RF powers also showed less mechanical deformation and improved quality of adhesion. The average (Ra) and root mean square (Rq) surface roughness parameters decreased, from 0.44 nm and 0.56 nm for 10 W to 0.33 nm and 0.42 nm for 100 W, respectively.

ZnO thin films have been grown by metalorganic chemical vapor deposition (MOCVD) and plasma-assisted (PA) MOCVD on c-axis-oriented sapphire (0001) and Si (001) substrates using the novel Zn(2-thenoyltrifluoroacetonate)2·N,N,N′,N′-tetramethylethylendiamine precursor. The structural, morphological, and optical properties of ZnO films have been investigated. The results show that the O2 PA growth results in highly c-axis-oriented hexagonal ZnO thin films also on cubic substrates. PA-MOCVD ZnO films have good optical properties, as inferred by the presence of a sharp and intense exciton in the dielectric function.