The mechanical properties of single-walled nanotubes (SWNTs) filled with small fullerenes (C20, C36 and C60) were investigated using molecular dynamics (MD) simulation. The interaction between carbon atoms was described by a combination of the many-body Brenner potential with a two-body pair potential. We found that below the critical value of the strain, the stress of SWNT increases linearly with the strain and the Young's modulus of certain SWNT with different filling densities is almost the same for small strain. It was also observed that the buckling force, which corresponds to the critical strain, becomes higher as the filling density of SWNT is increased in general. However, in the case of SWNT of larger radius filled with smaller fullerenes, the dependence of the buckling force on the filling density is expected to be different, which was attributive to the long-distance attractive interaction between atoms of fullerene and those of SWNT.

Ge-rich Ge 1−x−y Si x C y alloys have been grown on Si (100) substrates by plasma-enhanced rapid thermal chemical vapor deposition. It is found that there is a strong suppressive effect of C on the Ge composition and the growth rate. A possible mechanism for the suppressive effect is proposed. After calculations of atomic configuration, we obtain the relationship between the degree of suppression and the Ge/C atomic ratio. From the calculation results, a saturation tendency of the suppressive effect is expected with increasing Ge concentration in the growth of Ge 1−x−y Si x C y alloys.

The properties of a photoconductive ultraviolet detector based on a GaN epilayer grown on a 6H-SiC substrate using metal-organic chemical vapor deposition were investigated. We obtained the detectable energy span of the device up to the ultraviolet region by photocurrent measurement. The spectral responsivity remained nearly constant for wavelengths ranging from 250 to 365 nm and dropped by three orders of magnitude within 15 nm of the band edge from 365 nm to 380 nm.The detector was measured to have a responsivity of 133 A/W at a wavelength of 360 nm under a 5 V bias, and the voltage-dependent responsivity was evatuated. Furthermore, a convenient method to determine the response time was developed. The relationship between response time and bias was obtained.

In this paper, the deposition of energetic C 2 clusters on silicon and diamond surfaces is investigated by molecular dynamics simulation. The impact energy ranges from 0.5 to 60 eV in order to compare with experiments of diamondlike carbon ͑DLC͒ film synthesis by femtosecond ͑fs͒ pulsed laser deposition. The influence of the impact energy on the deposition dynamics as well as the structure of the synthesized films is addressed. Simulations show that at the earlier stage of the deposition, the mobility of surface atoms, especially the recoil atoms, is enhanced at elevated incident energies, and contributes to the smooth growth of DLC films. Our results are consistent with experimental observations.