The transport properties of B-doped single-walled carbon nanotubes (SWNTs) are studied from both experimental and theoretical standpoints. Experimentally, it is found that the semiconducting behavior of SWNTs is drastically changed after B-doping, and the unusual abrupt current drops are observed at low temperatures, which may imply the possibility of superconducting transition in B-doped SWNTs. Using the density-functional tight-binding calculation, it is observed that B-doping induces the presence of density of state peaks near the Fermi level which shifts toward the valence band region, showing a clear charge-transfer characteristic, which agrees well with the experimental observations.

The growth reaction mechanism was experimentally investigated for TEGa and TMSb used for MOCVD GaSb epitaxial growth. The variations of growth rate, substrate temperature, the V/III ratio and the mole-fraction of III and V source gases, were detailly considered and investigated with regard to their effect on electrical and optical properties were measured during the epitaxial process. The experimental results were used to provide an inspection on defects interaction mechanisms and on the type of conductivity. Based on the investigation of growth mechanism, at 470°, a high quality GaSb epitaxial film 1 with 3 mobility, 634 cm2/V*sec and low hole concentration, 1.67x1016 cm−2 was obtained.