Physical vapor deposition, nanowires

Kong, Y.C., D.P. Yu, B. Zhang, W. Fang and S.Q. Feng (2001). Ultraviolet-emitting ZnO nanowires synthesized by a physical vapor deposition approach. Applied Physics Letters, 78(4), 407 109. 

In the case of ex situ application of an elemental catalyst, a number of physical vapor deposition techniques can be utilized, including sputtering and molecular beam epitaxy. In this way, a few to tens of monolayers of the catalyst metal are deposited onto the substrate, which is then inserted into the CVD reactor. For both of these choices the rationale for depositing a few monolayers of the catalyst is twofold. First, an extremely low coverage of the catalyst material will facilitate islanding, which is critical to nanowire formation. Second, the amount of catalyst on the substrate will dictate the size of the metal islands, which in turn will dictate the diameter of the nanowires. The primary drawback to these two approaches is that the size distribution of the islands caimot be readily controlled. 

Cross, C. E., Hemminger, J. C., and Penner, R. M. 2007. Physical vapor deposition of one-dimensional nanoparticle arrays on graphite Seeding the electrodeposition of gold nanowires. Langmuir 23 10372-10379. 

Jash, R and Trenary, M. Synthesis of crystaUine boron nanoribbons and calcium hexaboride nanowires by low pressure chemical vapor deposition. Journal of Physics Cortference Series, 21MI9,176,012011(1-11). 

Synthesis mefliods of NWs basically include both vapor phase and solution techniques. Compared to physical methods such as nanohthography and other patterning techniques, chemical methods have been more versatile and effective in the synthesis of these nanowires. The chemical synthesis includes various methods thermal evaporation, chemical vapor-phase deposition, metal-organic chemical... 

---