Modeling nanoscale gas sensors under realistic conditions: Computational screening of metal-doped carbon nanotubes

Physical Review B 81, 245429 (2010)

Modeling nanoscale gas sensors under realistic conditions: Computational screening of metal-doped carbon nanotubes

J. M. García-Lastra, D.J. Mowbray, K. S. Thygesen, A. Rubio, K.W. Jacobsen

We use computational screening to systematically investigate the use of transition metal doped carbon nanotubes for chemical gas sensing. For a set of relevant target molecules (CO, NH₃, H₂S) and the main components of air (N₂, O₂, H₂O), we calculate the binding energy and change in conductance upon adsorption on a metal atom occupying a vacancy of a (6,6) carbon nanotube. Based on these descriptors, we identify the most promising dopant candidates for detection of a given target molecule. From the fractional coverage of the metal sites in thermal equilibrium with air, we estimate the change in the nanotube resistance per doping site as a function of the target molecule concentration assuming charge transport in the diffusive regime. Our analysis points to Ni-doped nanotubes as candidates for CO sensors working under typical atmospheric conditions.

Additional Information

Download
Preprint - 438.15 KB
Doi
http://dx.doi.org/10.1103/PhysRevB.81.245429
arxiv
http://arxiv.org/abs/1001.2538

Related Projects

Related Research Areas