Nano-electrical structure of hybridization (metal nanotube) and reaction with hydrogen gas and fluorine (based on nano-microelectronics) (educational-research doctorate)

Researcher  and author: PhD student   Afshin Rashid



Note: In the electrical structure of hybridization (metallic nanotube) reacting with hydrogen gas and fluorine, by entering  SP3, it converts the electrical structure of metallic nanotube hybridization into semiconductor. 

These reactions sometimes damage the walls of the nanotubes, resulting in the formation of amorphous carbon or graphite layer structures. With the hydrogenation of single-walled nanotubes, the semiconductor nature of SWCNTs increases at room temperature. Strong plasma or high temperature reaction etching the wall of metal nanotubes. That semiconductor SWCNTs are not harmed. Therefore controlling the reaction conditions is very important. In nanotubes, reaction with methane plasma  eliminates metal SWCNTs without destroying  semiconductor SWCNTs. The  method uses nano-molecular-weight hydrogen plasma  in which hydrogen plasma is  used to convert metal SWCNTs to  semiconductor SWCNTs, in  which case the nanotube walls are  not destroyed and etched. These reactions occurring in the gas phase  lead to the in situ, large-scale fabrication of TFTS and  FETS with semiconductor nanotubes,  which is crucial for commercializing high-efficiency nanotube-based equipment  . By selecting the appropriate reactant gases, this  method can also be used for selective reactivity with  semiconductor nanotubes. With the reaction of SWCNTs SO3 as  under neutral gas in the presence of gas; the reactive gas inside the furnace at 400◦C, the semiconductor nanotubes preferably  react with the gas  . The nanotubes are then heated to 900 °  C to recover the defect metal nanotubes  . This process is  an easy way to enrich the nanotube sample Metal nanotubes. Mass production of metallic nanotubes  can be achieved by more precisely controlling the reaction conditions  and eventually increasing the scale of its  production costs including conductive films and  transparent electrodes.


In general, based on the rate of reaction, the electrochemical  covalent selectivity of metal nanotubes can  be divided into two groups: 

1. First, the nanotube metal to a semiconductor,  turn that off of the type of metal  used and end the nanotube metal is  the first reaction along with the establishment of the electron and the  loss of symmetry and a dash of energy  at the Fermi level nanotube metal Creates. 

2. The second reaction conjugate all systems into a  series of smaller aromatic compounds through the  open CC bonds in the structure of nanotubes  makes. The end result of both modes is  to obtain semiconductor  nanotubes that are suitable for the manufacture of nanoelectronic devices  .


 In selective covalent reactions, the concentration of the  reactant is always important. And when the reactant concentration is high  , both types of nanotubes are affected by the reaction  . For example, in the case of FETS, increasing the  reactant concentration reduces the Off current  and thus increases the Off / On ratio to more than  105. On the other hand, it reduces the severe mobility reaction  , which is another important parameter  for electronic equipment. Therefore, there must be a  balance between the rate of reaction progress and the final efficiency  of the equipment.




Conclusion :

There are several  drawbacks to covalent methods  . First of all, most nanotubes become functional  and, as a result, the electronic structure of  SWCNTs is defective. Second  , it is difficult to purify the product from amorphous carbon due to the strong reaction  . Most importantly, there is  no covalent reaction after  which the nanotube (m, n) can be  purified individually.


Author: Engineer Afshin Rashid 

PhD student of Nano-Microelectronics at Islamic Azad University, Science and Research Branch, Tehran