By combining ab initio simulations with state-of-the-art electron microscopy and electron energy loss spectroscopy, we study the mechanism of electron beam damage in nitrogen-doped graphene and carbon nanotubes. Our results show that the incorporation of nitrogen atoms results in noticeable knock-on damage in these structures already at an acceleration voltage of 80 kV, at which essentially no ...

First-principle calculations have been carried out to investigate structural stabilities, electronic structures and optical properties of tungsten doped bismuth oxychloride (BiOCl). The structures of substitutional and interstitial tungsten, and in the form of WO6-ligand-doped BiOCl are examined. The substitutional and interstitial tungsten doping leads to discrete midgap states within the forb...

Electron transport in bilayer phosphorene is studied using the first-principles and nonequilibrium Green’s function formalism. We have explored interlayer properties of a vertically stacked structure with paired substitutional doping. The electron are calculated compared doping, which shows tunable anisotropic nature doped I–V characteristics. Further, to understand role played by dopants, quan...

Titanium dioxide (TiO2) is the leading material for self-cleaning applications due to its chemical inertness, mechanical robustness, durability to extended photocatalytic cycling, low cost and high photocatalytic activity. There has been a concerted effort to try and improve the material’s functional properties through impurity doping; altering the band structure and electronic transport proper...

Ion implantation of dopant impurities to form p-n junctions and other doped regions in silicon transistors has evolved from an experimental curiosity in solid-state physics to become a dominant technology in today’s integrated circuit manufacturing. This paper traces the key inventions and early developments in ion beam doping concepts from the early 1950’s through the 1970’s as they were appli...

We report on the lattice location of ion-implanted Cu in pand n-Si using the emission channeling technique. Following room-temperature implantation, the majority of Cu was found on near-substitutional sites in both pand n-Si. Annealing in the temperature range 200-600°C resulted in changes of near-substitutional Cu to random sites in p-Si, while in n-Si all of the near-substitutional Cu was con...

Substitutional hydrogen at oxygen site (HO) is well-known to be a robust source of n-type conductivity in ZnO, but a puzzling aspect is that the doping limit by hydrogen is only about 10(18) cm(-3), even if solubility limit is much higher. Another puzzling aspect of ZnO is persistent photoconductivity, which prevents the wide applications of the ZnO-based thin film transistor. Up to now, there ...