Size-Dependent Materials Properties Toward a Universal Equation

Due to the lack of experimental values concerning some material properties at the nanoscale, it is interesting to evaluate this theoretically. Through a “top–down” approach, a universal equation is developed here which is particularly helpful when experiments are difficult to lead on a specific material property. It only requires the knowledge of the surface area to volume ratio of the nanomaterial, its size as well as the statistic (Fermi–Dirac or Bose–Einstein) followed by the particles involved in the considered material property. Comparison between different existing theoretical models and the proposed equation is done

Special electronic structures and quantum conduction of B/P co-doping carbon nanotubes under electric field using the first principle

Boron (B)/phosphorus (P) doped single wall carbon nanotubes (B-PSWNTs) are studied by using the First- Principle method based on density function theory (DFT). Mayer bond order, band structure, electrons density and density of states are calculated. It concludes that the B-PSWNTs have special band structure which is quite different from BN nanotubes, and that metallic carbon nanotubes will be converted to semiconductor due to boron/phosphorus co-doping which breaks the symmetrical structure. The bonding forms in B-PSWNTs are investigated in detail. Besides, Mulliken charge population and the quantum conductance are also calculated to study the quantum transport characteristics of B-PSWNT hetero-junction. It is found that the position of p-n junction in this hetero-junction will be changed as the applied electric field increase and it performs the characteristics of diode.Comment: 11 pages, 6 fiugres, 2 table