Udo Schwingenschlogl

Abstract:

We study the potential of material simulations based on first-principles methods to predict gas sensing properties of 2D materials. This emerging class of materials is of particular interest to gas sensing applications due to high surface-to-volume ratios and chemical stability. We discuss in detail results of electron transport calculations within the Landauer-Büttiker formalism and compare the conclusions to analyses in terms of adsorption energies‚ charge transfers‚ and work functions. Specific examples include the effects of the interlayer interaction in bilayer MoS2 and WS2 on the gas sensing performance and the consequence of the presence of reactive Si in Si2BN. We also address the properties of C3N and para/meta-C3Si. Potential of very sensitive gas sensing is demonstrated for para-C3Si and is explained by the susceptibility of Dirac states to symmetry breaking distortions rather than by a mechanism based on charge transfer. Finally‚ the enhanced gas sensing performance of monovacant C6BN is studied and it is shown that the work function changes of both pristine and monovacant C6BN during gas adsorption do not correlate with the changes observed in the I-V characteristics.