Band gap opening in α-graphyne by adsorption of organic molecule

• Effect of TCNE on electronic property of α-graphyne is studied.
• TCNE is physisorbed on α-graphyne.
• Charge is transferred from graphyne to TCNE.
• Adsorption of TCNE molecule makes α-graphyne a semiconductor.
• Energy band gap is enhanced by increasing number of TCNE.

The lack of a band gap limits the application of graphyne in nanoelectronic devices. We have investigated possibility of opening a band gap in α-graphyne by adsorption of tetracyanoethylene. The electronic property of α-graphyne in the presence of different numbers of tetracyanoethylene has been studied using density functional theory. It is found that charge is transferred from graphyne sheet to tetracyanoethylene molecules. In the presence of this electron acceptor molecule, a semimetal α-graphyne shows semiconducting property. The energy band gap at the Dirac point is enhanced by increasing the number of tetracyanoethylene. Our results provide a simple method to create and control the band gap in α-graphyne.

The band gap opening in α-graphyne by adsorption of organic molecule has been studied using a density functional theory. Our results show that adsorption of tetracyanoethylene is a promising approach to modify electronic properties of α-graphyne.Figure optionsDownload as PowerPoint slide